Remove ErrorResponse (#7369)

* Refactor MySQLComStmtExecuteExecutor

* Refactor MySQLComStmtExecuteExecutor

* Use protocol framework to process internal COM_QUERY exception

* Use protocol framework to process internal COM_QUERY exception

* Refactor PostgreSQLComBindExecutor

* Refactor PostgreSQLComQueryExecutor

* Remove ErrorResponse

* Revise PostgreSQLCommandExecuteEngine

shardingsphere-proxy/shardingsphere-proxy-backend/src/main/java/org/apache/shardingsphere/proxy/backend/communication/DatabaseCommunicationEngine.java

@@ -31,8 +31,9 @@ public interface DatabaseCommunicationEngine {
      * Execute command.
      *
      * @return backend response
+     * @throws SQLException SQL exception
      */
-    BackendResponse execute();
+    BackendResponse execute() throws SQLException;
     
     /**
      * Goto next result value.

shardingsphere-proxy/shardingsphere-proxy-backend/src/main/java/org/apache/shardingsphere/proxy/backend/communication/jdbc/JDBCDatabaseCommunicationEngine.java

@@ -18,11 +18,10 @@
 package org.apache.shardingsphere.proxy.backend.communication.jdbc;
 
 import lombok.RequiredArgsConstructor;
-import org.apache.shardingsphere.infra.config.exception.ShardingSphereConfigurationException;
+import org.apache.shardingsphere.governance.core.event.persist.MetaDataPersistEvent;
+import org.apache.shardingsphere.governance.core.eventbus.ShardingSphereEventBus;
 import org.apache.shardingsphere.infra.config.properties.ConfigurationPropertyKey;
 import org.apache.shardingsphere.infra.context.SchemaContext;
-import org.apache.shardingsphere.governance.core.eventbus.ShardingSphereEventBus;
-import org.apache.shardingsphere.governance.core.event.persist.MetaDataPersistEvent;
 import org.apache.shardingsphere.infra.executor.sql.QueryResult;
 import org.apache.shardingsphere.infra.executor.sql.context.ExecutionContext;
 import org.apache.shardingsphere.infra.executor.sql.log.SQLLogger;
@@ -37,14 +36,12 @@ import org.apache.shardingsphere.proxy.backend.communication.DatabaseCommunicati
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.ConnectionStatus;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.execute.SQLExecuteEngine;
+import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.backend.exception.TableModifyInTransactionException;
 import org.apache.shardingsphere.proxy.backend.response.BackendResponse;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryData;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryResponse;
 import org.apache.shardingsphere.proxy.backend.response.update.UpdateResponse;
-import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
-import org.apache.shardingsphere.sharding.route.engine.exception.TableExistsException;
 import org.apache.shardingsphere.sql.parser.binder.metadata.table.TableMetaData;
 import org.apache.shardingsphere.sql.parser.binder.statement.SQLStatementContext;
 import org.apache.shardingsphere.sql.parser.binder.type.TableAvailable;
@@ -83,15 +80,10 @@ public final class JDBCDatabaseCommunicationEngine implements DatabaseCommunicat
     }
     
     @Override
-    public BackendResponse execute() {
-        try {
-            ExecutionContext executionContext = executeEngine.generateExecutionContext(sql);
-            logSQL(executionContext);
-            return doExecute(executionContext);
-        } catch (final TableExistsException | ShardingSphereConfigurationException | SQLException ex) {
-            // TODO Particular handling needed for `createTable` without shardingRule and dataNode.
-            return new ErrorResponse(ex);
-        }
+    public BackendResponse execute() throws SQLException {
+        ExecutionContext executionContext = executeEngine.generateExecutionContext(sql);
+        logSQL(executionContext);
+        return doExecute(executionContext);
     }
     
     private void logSQL(final ExecutionContext executionContext) {
@@ -106,7 +98,7 @@ public final class JDBCDatabaseCommunicationEngine implements DatabaseCommunicat
         }
         SQLStatementContext<?> sqlStatementContext = executionContext.getSqlStatementContext();
         if (isExecuteDDLInXATransaction(sqlStatementContext.getSqlStatement())) {
-            return new ErrorResponse(new TableModifyInTransactionException(getTableName(sqlStatementContext)));
+            throw new TableModifyInTransactionException(getTableName(sqlStatementContext));
         }
         response = executeEngine.execute(executionContext);
         refreshTableMetaData(executionContext.getSqlStatementContext());

shardingsphere-proxy/shardingsphere-proxy-backend/src/main/java/org/apache/shardingsphere/proxy/backend/response/error/ErrorResponse.java

-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.shardingsphere.proxy.backend.response.error;
-
-import lombok.Getter;
-import lombok.RequiredArgsConstructor;
-import org.apache.shardingsphere.proxy.backend.response.BackendResponse;
-
-/**
- * Error response.
- */
-@RequiredArgsConstructor
-@Getter
-public final class ErrorResponse implements BackendResponse {
-    
-    private final Exception cause;
-}

shardingsphere-proxy/shardingsphere-proxy-backend/src/main/java/org/apache/shardingsphere/proxy/backend/text/admin/BroadcastBackendHandler.java

@@ -20,16 +20,14 @@ package org.apache.shardingsphere.proxy.backend.text.admin;
 import lombok.RequiredArgsConstructor;
 import org.apache.shardingsphere.proxy.backend.communication.DatabaseCommunicationEngineFactory;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
+import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.backend.response.BackendResponse;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryData;
 import org.apache.shardingsphere.proxy.backend.response.update.UpdateResponse;
-import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.backend.text.TextProtocolBackendHandler;
 import org.apache.shardingsphere.sql.parser.sql.common.statement.SQLStatement;
 
-import java.util.Collection;
-import java.util.LinkedList;
+import java.sql.SQLException;
 
 /**
  * Backend handler for broadcast.
@@ -46,19 +44,13 @@ public final class BroadcastBackendHandler implements TextProtocolBackendHandler
     private final BackendConnection backendConnection;
     
     @Override
-    public BackendResponse execute() {
-        Collection<BackendResponse> responses = new LinkedList<>();
+    public BackendResponse execute() throws SQLException {
         String originalSchema = backendConnection.getSchema();
         for (String each : ProxyContext.getInstance().getAllSchemaNames()) {
             backendConnection.setCurrentSchema(each);
-            responses.add(databaseCommunicationEngineFactory.newTextProtocolInstance(sqlStatement, sql, backendConnection).execute());
+            databaseCommunicationEngineFactory.newTextProtocolInstance(sqlStatement, sql, backendConnection).execute();
         }
         backendConnection.setCurrentSchema(originalSchema);
-        for (BackendResponse each : responses) {
-            if (each instanceof ErrorResponse) {
-                return each;
-            }
-        }
         return new UpdateResponse();
     }
     

shardingsphere-proxy/shardingsphere-proxy-backend/src/main/java/org/apache/shardingsphere/proxy/backend/text/admin/RDLBackendHandler.java

@@ -18,22 +18,21 @@
 package org.apache.shardingsphere.proxy.backend.text.admin;
 
 import lombok.RequiredArgsConstructor;
+import org.apache.shardingsphere.governance.core.event.persist.DataSourcePersistEvent;
+import org.apache.shardingsphere.governance.core.event.persist.RulePersistEvent;
+import org.apache.shardingsphere.governance.core.event.persist.SchemaNamePersistEvent;
+import org.apache.shardingsphere.governance.core.eventbus.ShardingSphereEventBus;
 import org.apache.shardingsphere.infra.config.RuleConfiguration;
 import org.apache.shardingsphere.infra.config.datasource.DataSourceConfiguration;
 import org.apache.shardingsphere.infra.context.impl.StandardSchemaContexts;
 import org.apache.shardingsphere.infra.database.type.DatabaseType;
-import org.apache.shardingsphere.governance.core.eventbus.ShardingSphereEventBus;
-import org.apache.shardingsphere.governance.core.event.persist.DataSourcePersistEvent;
-import org.apache.shardingsphere.governance.core.event.persist.RulePersistEvent;
-import org.apache.shardingsphere.governance.core.event.persist.SchemaNamePersistEvent;
 import org.apache.shardingsphere.infra.yaml.swapper.YamlRuleConfigurationSwapperEngine;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
+import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.backend.exception.DBCreateExistsException;
 import org.apache.shardingsphere.proxy.backend.response.BackendResponse;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryData;
 import org.apache.shardingsphere.proxy.backend.response.update.UpdateResponse;
-import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.backend.text.TextProtocolBackendHandler;
 import org.apache.shardingsphere.proxy.config.util.DataSourceParameterConverter;
 import org.apache.shardingsphere.proxy.config.yaml.YamlDataSourceParameter;
@@ -67,17 +66,17 @@ public final class RDLBackendHandler implements TextProtocolBackendHandler {
     private final SQLStatement sqlStatement;
     
     @Override
-    public BackendResponse execute() {
+    public BackendResponse execute() throws SQLException {
         SQLStatementContext<?> context = getSQLStatementContext();
         if (!isRegistryCenterExisted()) {
-            return new ErrorResponse(new SQLException("No Registry center to execute `%s` SQL", context.getClass().getSimpleName()));
+            throw new SQLException(String.format("No Registry center to execute `%s` SQL", context.getClass().getSimpleName()));
         }
         return getBackendResponse(context);
     }
     
     private BackendResponse execute(final CreateDatabaseStatementContext context) {
         if (ProxyContext.getInstance().getAllSchemaNames().contains(context.getSqlStatement().getDatabaseName())) {
-            return new ErrorResponse(new DBCreateExistsException(context.getSqlStatement().getDatabaseName()));
+            throw new DBCreateExistsException(context.getSqlStatement().getDatabaseName());
         }
         // TODO Need to get the executed feedback from registry center for returning.
         ShardingSphereEventBus.getInstance().post(new SchemaNamePersistEvent(context.getSqlStatement().getDatabaseName(), false));
@@ -88,7 +87,7 @@ public final class RDLBackendHandler implements TextProtocolBackendHandler {
     
     private BackendResponse execute(final DropDatabaseStatementContext context) {
         if (!ProxyContext.getInstance().getAllSchemaNames().contains(context.getSqlStatement().getDatabaseName())) {
-            return new ErrorResponse(new DBCreateExistsException(context.getSqlStatement().getDatabaseName()));
+            throw new DBCreateExistsException(context.getSqlStatement().getDatabaseName());
         }
         // TODO Need to get the executed feedback from registry center for returning.
         ShardingSphereEventBus.getInstance().post(new SchemaNamePersistEvent(context.getSqlStatement().getDatabaseName(), true));
@@ -109,8 +108,8 @@ public final class RDLBackendHandler implements TextProtocolBackendHandler {
     }
     
     private BackendResponse execute(final CreateShardingRuleStatementContext context) {
-        YamlShardingRuleConfiguration configurations = new CreateShardingRuleStatementContextConverter().convert(context);
-        Collection<RuleConfiguration> rules = new YamlRuleConfigurationSwapperEngine().swapToRuleConfigurations(Collections.singleton(configurations));
+        YamlShardingRuleConfiguration configs = new CreateShardingRuleStatementContextConverter().convert(context);
+        Collection<RuleConfiguration> rules = new YamlRuleConfigurationSwapperEngine().swapToRuleConfigurations(Collections.singleton(configs));
         // TODO Need to get the executed feedback from registry center for returning.
         ShardingSphereEventBus.getInstance().post(new RulePersistEvent(backendConnection.getSchema(), rules));
         UpdateResponse result = new UpdateResponse();

shardingsphere-proxy/shardingsphere-proxy-backend/src/main/java/org/apache/shardingsphere/proxy/backend/text/admin/ShowTablesBackendHandler.java

@@ -23,12 +23,11 @@ import org.apache.shardingsphere.infra.executor.sql.raw.execute.result.query.Que
 import org.apache.shardingsphere.proxy.backend.communication.DatabaseCommunicationEngine;
 import org.apache.shardingsphere.proxy.backend.communication.DatabaseCommunicationEngineFactory;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
+import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.backend.exception.NoDatabaseSelectedException;
 import org.apache.shardingsphere.proxy.backend.response.BackendResponse;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryData;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryResponse;
-import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.backend.text.TextProtocolBackendHandler;
 import org.apache.shardingsphere.sql.parser.sql.common.statement.SQLStatement;
 
@@ -53,10 +52,10 @@ public final class ShowTablesBackendHandler implements TextProtocolBackendHandle
     private DatabaseCommunicationEngine databaseCommunicationEngine;
     
     @Override
-    public BackendResponse execute() {
+    public BackendResponse execute() throws SQLException {
         SchemaContext context = ProxyContext.getInstance().getSchema(backendConnection.getSchema());
         if (null == context) {
-            return new ErrorResponse(new NoDatabaseSelectedException());
+            throw new NoDatabaseSelectedException();
         }
         if (!context.isComplete()) {
             return getDefaultQueryResponse(backendConnection.getSchema());

shardingsphere-proxy/shardingsphere-proxy-backend/src/main/java/org/apache/shardingsphere/proxy/backend/text/admin/UnicastBackendHandler.java

@@ -22,11 +22,10 @@ import org.apache.shardingsphere.infra.context.SchemaContext;
 import org.apache.shardingsphere.proxy.backend.communication.DatabaseCommunicationEngine;
 import org.apache.shardingsphere.proxy.backend.communication.DatabaseCommunicationEngineFactory;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
+import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.backend.exception.NoDatabaseSelectedException;
 import org.apache.shardingsphere.proxy.backend.response.BackendResponse;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryData;
-import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.backend.text.TextProtocolBackendHandler;
 import org.apache.shardingsphere.sql.parser.sql.common.statement.SQLStatement;
 
@@ -50,11 +49,11 @@ public final class UnicastBackendHandler implements TextProtocolBackendHandler {
     private DatabaseCommunicationEngine databaseCommunicationEngine;
     
     @Override
-    public BackendResponse execute() {
+    public BackendResponse execute() throws SQLException {
         if (null == backendConnection.getSchema()) {
             Map<String, SchemaContext> schemaContexts = ProxyContext.getInstance().getSchemaContexts().getSchemaContexts();
             if (schemaContexts.isEmpty()) {
-                return new ErrorResponse(new NoDatabaseSelectedException());
+                throw new NoDatabaseSelectedException();
             }
             // TODO we should remove set default ShardingSphere schema after parser can recognize all DAL broadcast SQL.
             backendConnection.setCurrentSchema(schemaContexts.keySet().iterator().next());

shardingsphere-proxy/shardingsphere-proxy-backend/src/main/java/org/apache/shardingsphere/proxy/backend/text/admin/UseDatabaseBackendHandler.java

@@ -19,12 +19,11 @@ package org.apache.shardingsphere.proxy.backend.text.admin;
 
 import lombok.RequiredArgsConstructor;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
+import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.backend.exception.UnknownDatabaseException;
 import org.apache.shardingsphere.proxy.backend.response.BackendResponse;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryData;
 import org.apache.shardingsphere.proxy.backend.response.update.UpdateResponse;
-import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.backend.text.TextProtocolBackendHandler;
 import org.apache.shardingsphere.sql.parser.sql.common.util.SQLUtil;
 import org.apache.shardingsphere.sql.parser.sql.dialect.statement.mysql.dal.MySQLUseStatement;
@@ -48,7 +47,7 @@ public final class UseDatabaseBackendHandler implements TextProtocolBackendHandl
             backendConnection.setCurrentSchema(schema);
             return new UpdateResponse();
         }
-        return new ErrorResponse(new UnknownDatabaseException(schema));
+        throw new UnknownDatabaseException(schema);
         
     }
     

shardingsphere-proxy/shardingsphere-proxy-backend/src/main/java/org/apache/shardingsphere/proxy/backend/text/query/QueryBackendHandler.java

@@ -23,12 +23,11 @@ import org.apache.shardingsphere.infra.executor.sql.raw.execute.result.query.Que
 import org.apache.shardingsphere.proxy.backend.communication.DatabaseCommunicationEngine;
 import org.apache.shardingsphere.proxy.backend.communication.DatabaseCommunicationEngineFactory;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
+import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.backend.exception.NoDatabaseSelectedException;
 import org.apache.shardingsphere.proxy.backend.response.BackendResponse;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryData;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryResponse;
-import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.backend.text.TextProtocolBackendHandler;
 import org.apache.shardingsphere.sql.parser.sql.common.statement.SQLStatement;
 
@@ -53,10 +52,10 @@ public final class QueryBackendHandler implements TextProtocolBackendHandler {
     private DatabaseCommunicationEngine databaseCommunicationEngine;
     
     @Override
-    public BackendResponse execute() {
+    public BackendResponse execute() throws SQLException {
         SchemaContext context = ProxyContext.getInstance().getSchema(backendConnection.getSchema());
         if (null == context) {
-            return new ErrorResponse(new NoDatabaseSelectedException());
+            throw new NoDatabaseSelectedException();
         }
         if (!context.isComplete()) {
             return getDefaultQueryResponse(backendConnection.getSchema());

shardingsphere-proxy/shardingsphere-proxy-backend/src/main/java/org/apache/shardingsphere/proxy/backend/text/sctl/explain/ShardingCTLExplainBackendHandler.java

@@ -23,11 +23,10 @@ import org.apache.shardingsphere.infra.executor.sql.context.ExecutionUnit;
 import org.apache.shardingsphere.infra.executor.sql.raw.execute.result.query.QueryHeader;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.wrapper.StatementExecutorWrapper;
+import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.backend.response.BackendResponse;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryData;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryResponse;
-import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.backend.text.TextProtocolBackendHandler;
 import org.apache.shardingsphere.proxy.backend.text.sctl.exception.InvalidShardingCTLFormatException;
 
@@ -55,7 +54,7 @@ public final class ShardingCTLExplainBackendHandler implements TextProtocolBacke
     public BackendResponse execute() {
         Optional<ShardingCTLExplainStatement> explainStatement = new ShardingCTLExplainParser(sql).doParse();
         if (!explainStatement.isPresent()) {
-            return new ErrorResponse(new InvalidShardingCTLFormatException(sql));
+            throw new InvalidShardingCTLFormatException(sql);
         }
         SchemaContext schema = ProxyContext.getInstance().getSchema(backendConnection.getSchema());
         StatementExecutorWrapper statementExecutorWrapper =

shardingsphere-proxy/shardingsphere-proxy-backend/src/main/java/org/apache/shardingsphere/proxy/backend/text/sctl/hint/ShardingCTLHintBackendHandler.java

@@ -17,16 +17,15 @@
 
 package org.apache.shardingsphere.proxy.backend.text.sctl.hint;
 
+import org.apache.shardingsphere.infra.config.properties.ConfigurationPropertyKey;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
 import org.apache.shardingsphere.proxy.backend.response.BackendResponse;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryData;
 import org.apache.shardingsphere.proxy.backend.text.TextProtocolBackendHandler;
 import org.apache.shardingsphere.proxy.backend.text.sctl.exception.InvalidShardingCTLFormatException;
 import org.apache.shardingsphere.proxy.backend.text.sctl.hint.internal.HintCommand;
 import org.apache.shardingsphere.proxy.backend.text.sctl.hint.internal.HintCommandExecutor;
 import org.apache.shardingsphere.proxy.backend.text.sctl.hint.internal.HintCommandExecutorFactory;
-import org.apache.shardingsphere.infra.config.properties.ConfigurationPropertyKey;
 
 import java.sql.SQLException;
 import java.util.Optional;
@@ -55,7 +54,7 @@ public final class ShardingCTLHintBackendHandler implements TextProtocolBackendH
         }
         Optional<ShardingCTLHintStatement> shardingTCLStatement = new ShardingCTLHintParser(sql).doParse();
         if (!shardingTCLStatement.isPresent()) {
-            return new ErrorResponse(new InvalidShardingCTLFormatException(sql));
+            throw new InvalidShardingCTLFormatException(sql);
         }
         HintCommand hintCommand = shardingTCLStatement.get().getHintCommand();
         hintCommandExecutor = HintCommandExecutorFactory.newInstance(hintCommand, backendConnection, sql);

shardingsphere-proxy/shardingsphere-proxy-backend/src/main/java/org/apache/shardingsphere/proxy/backend/text/sctl/hint/internal/executor/HintErrorParameterExecutor.java

@@ -19,7 +19,6 @@ package org.apache.shardingsphere.proxy.backend.text.sctl.hint.internal.executor
 
 import lombok.RequiredArgsConstructor;
 import org.apache.shardingsphere.proxy.backend.response.BackendResponse;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
 import org.apache.shardingsphere.proxy.backend.text.sctl.exception.UnsupportedShardingCTLTypeException;
 import org.apache.shardingsphere.proxy.backend.text.sctl.hint.internal.command.HintErrorParameterCommand;
 
@@ -33,6 +32,6 @@ public final class HintErrorParameterExecutor extends AbstractHintUpdateExecutor
     
     @Override
     public BackendResponse execute(final HintErrorParameterCommand command) {
-        return new ErrorResponse(new UnsupportedShardingCTLTypeException(sql));
+        throw new UnsupportedShardingCTLTypeException(sql);
     }
 }

shardingsphere-proxy/shardingsphere-proxy-backend/src/main/java/org/apache/shardingsphere/proxy/backend/text/sctl/set/ShardingCTLSetBackendHandler.java

@@ -19,7 +19,6 @@ package org.apache.shardingsphere.proxy.backend.text.sctl.set;
 
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
 import org.apache.shardingsphere.proxy.backend.response.BackendResponse;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryData;
 import org.apache.shardingsphere.proxy.backend.response.update.UpdateResponse;
 import org.apache.shardingsphere.proxy.backend.text.TextProtocolBackendHandler;
@@ -47,16 +46,16 @@ public final class ShardingCTLSetBackendHandler implements TextProtocolBackendHa
     public BackendResponse execute() {
         Optional<ShardingCTLSetStatement> shardingTCLStatement = new ShardingCTLSetParser(sql).doParse();
         if (!shardingTCLStatement.isPresent()) {
-            return new ErrorResponse(new InvalidShardingCTLFormatException(sql));
+            throw new InvalidShardingCTLFormatException(sql);
         }
         if ("TRANSACTION_TYPE".equals(shardingTCLStatement.get().getKey())) {
             try {
                 backendConnection.setTransactionType(TransactionType.valueOf(shardingTCLStatement.get().getValue()));
             } catch (final IllegalArgumentException ex) {
-                return new ErrorResponse(new UnsupportedShardingCTLTypeException(sql));
+                throw new UnsupportedShardingCTLTypeException(sql);
             }
         } else {
-            return new ErrorResponse(new UnsupportedShardingCTLTypeException(sql));
+            throw new UnsupportedShardingCTLTypeException(sql);
         }
         return new UpdateResponse();
     }

shardingsphere-proxy/shardingsphere-proxy-backend/src/main/java/org/apache/shardingsphere/proxy/backend/text/sctl/show/ShardingCTLShowBackendHandler.java

@@ -21,7 +21,6 @@ import org.apache.shardingsphere.infra.executor.sql.raw.execute.result.query.Que
 import org.apache.shardingsphere.infra.merge.result.MergedResult;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
 import org.apache.shardingsphere.proxy.backend.response.BackendResponse;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryData;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryResponse;
 import org.apache.shardingsphere.proxy.backend.text.TextProtocolBackendHandler;
@@ -55,7 +54,7 @@ public final class ShardingCTLShowBackendHandler implements TextProtocolBackendH
     public BackendResponse execute() {
         Optional<ShardingCTLShowStatement> showStatement = new ShardingCTLShowParser(sql).doParse();
         if (!showStatement.isPresent()) {
-            return new ErrorResponse(new InvalidShardingCTLFormatException(sql));
+            throw new InvalidShardingCTLFormatException(sql);
         }
         switch (showStatement.get().getValue()) {
             case "TRANSACTION_TYPE":
@@ -63,7 +62,7 @@ public final class ShardingCTLShowBackendHandler implements TextProtocolBackendH
             case "CACHED_CONNECTIONS":
                 return createResponsePackets("CACHED_CONNECTIONS", backendConnection.getConnectionSize());
             default:
-                return new ErrorResponse(new UnsupportedShardingCTLTypeException(sql));
+                throw new UnsupportedShardingCTLTypeException(sql);
         }
     }
     

shardingsphere-proxy/shardingsphere-proxy-backend/src/main/java/org/apache/shardingsphere/proxy/backend/text/transaction/TransactionBackendHandler.java

@@ -20,7 +20,6 @@ package org.apache.shardingsphere.proxy.backend.text.transaction;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendTransactionManager;
 import org.apache.shardingsphere.proxy.backend.response.BackendResponse;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryData;
 import org.apache.shardingsphere.proxy.backend.response.update.UpdateResponse;
 import org.apache.shardingsphere.proxy.backend.text.TextProtocolBackendHandler;
@@ -44,15 +43,7 @@ public final class TransactionBackendHandler implements TextProtocolBackendHandl
     }
     
     @Override
-    public BackendResponse execute() {
-        try {
-            return doTransaction();
-        } catch (final SQLException ex) {
-            return new ErrorResponse(ex);
-        }
-    }
-    
-    private BackendResponse doTransaction() throws SQLException {
+    public BackendResponse execute() throws SQLException {
         switch (operationType) {
             case BEGIN:
                 backendTransactionManager.begin();

shardingsphere-proxy/shardingsphere-proxy-backend/src/test/java/org/apache/shardingsphere/proxy/backend/text/admin/BroadcastBackendHandlerTest.java

@@ -26,10 +26,9 @@ import org.apache.shardingsphere.infra.database.type.dialect.MySQLDatabaseType;
 import org.apache.shardingsphere.proxy.backend.communication.DatabaseCommunicationEngine;
 import org.apache.shardingsphere.proxy.backend.communication.DatabaseCommunicationEngineFactory;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
+import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.backend.response.BackendResponse;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
 import org.apache.shardingsphere.proxy.backend.response.update.UpdateResponse;
-import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.sql.parser.sql.common.statement.SQLStatement;
 import org.junit.Before;
 import org.junit.Test;
@@ -78,7 +77,7 @@ public final class BroadcastBackendHandlerTest {
     }
     
     @Test
-    public void assertExecuteSuccess() {
+    public void assertExecuteSuccess() throws SQLException {
         mockDatabaseCommunicationEngine(new UpdateResponse());
         BroadcastBackendHandler broadcastBackendHandler = new BroadcastBackendHandler("SET timeout = 1000", mock(SQLStatement.class), backendConnection);
         setBackendHandlerFactory(broadcastBackendHandler);
@@ -97,17 +96,7 @@ public final class BroadcastBackendHandlerTest {
         return result;
     }
     
-    @Test
-    public void assertExecuteFailure() {
-        ErrorResponse errorResponse = new ErrorResponse(new SQLException("no reason", "X999", -1));
-        mockDatabaseCommunicationEngine(errorResponse);
-        BroadcastBackendHandler broadcastBackendHandler = new BroadcastBackendHandler("SET timeout = 1000", mock(SQLStatement.class), backendConnection);
-        setBackendHandlerFactory(broadcastBackendHandler);
-        assertThat(broadcastBackendHandler.execute(), instanceOf(ErrorResponse.class));
-        verify(databaseCommunicationEngine, times(10)).execute();
-    }
-    
-    private void mockDatabaseCommunicationEngine(final BackendResponse backendResponse) {
+    private void mockDatabaseCommunicationEngine(final BackendResponse backendResponse) throws SQLException {
         when(databaseCommunicationEngine.execute()).thenReturn(backendResponse);
         when(databaseCommunicationEngineFactory.newTextProtocolInstance(any(), anyString(), any())).thenReturn(databaseCommunicationEngine);
     }

shardingsphere-proxy/shardingsphere-proxy-backend/src/test/java/org/apache/shardingsphere/proxy/backend/text/admin/RDLBackendHandlerTest.java

@@ -25,11 +25,10 @@ import org.apache.shardingsphere.infra.context.SchemaContexts;
 import org.apache.shardingsphere.infra.context.impl.StandardSchemaContexts;
 import org.apache.shardingsphere.infra.database.type.dialect.MySQLDatabaseType;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
+import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.backend.exception.DBCreateExistsException;
 import org.apache.shardingsphere.proxy.backend.response.BackendResponse;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
 import org.apache.shardingsphere.proxy.backend.response.update.UpdateResponse;
-import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.rdl.parser.statement.rdl.CreateDataSourcesStatement;
 import org.apache.shardingsphere.rdl.parser.statement.rdl.CreateShardingRuleStatement;
 import org.apache.shardingsphere.sql.parser.sql.common.statement.ddl.CreateDatabaseStatement;
@@ -39,11 +38,14 @@ import org.junit.Before;
 import org.junit.Test;
 
 import java.lang.reflect.Field;
+import java.sql.SQLException;
 import java.util.Collections;
 import java.util.Map;
 import java.util.Properties;
 
 import static org.hamcrest.CoreMatchers.instanceOf;
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertThat;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
@@ -60,40 +62,51 @@ public final class RDLBackendHandlerTest {
     }
     
     @Test
-    public void assertExecuteCreateDatabaseContext() {
+    public void assertExecuteCreateDatabaseContext() throws SQLException {
         BackendConnection connection = mock(BackendConnection.class);
         when(connection.getSchema()).thenReturn("schema");
         RDLBackendHandler executeEngine = new RDLBackendHandler(connection, new CreateDatabaseStatement("new_db"));
-        BackendResponse response = executeEngine.execute();
-        assertThat(response, instanceOf(ErrorResponse.class));
+        try {
+            executeEngine.execute();
+        } catch (final SQLException ex) {
+            assertThat(ex.getMessage(), is("No Registry center to execute `CreateDatabaseStatementContext` SQL"));
+        }
         setGovernanceSchemaContexts(true);
-        response = executeEngine.execute();
+        BackendResponse response = executeEngine.execute();
         assertThat(response, instanceOf(UpdateResponse.class));
     }
     
     @Test
-    public void assertExecuteDropDatabaseContext() {
+    public void assertExecuteDropDatabaseContext() throws SQLException {
         BackendConnection connection = mock(BackendConnection.class);
         when(connection.getSchema()).thenReturn("schema");
         RDLBackendHandler executeEngine = new RDLBackendHandler(connection, new DropDatabaseStatement("schema"));
-        BackendResponse response = executeEngine.execute();
-        assertThat(response, instanceOf(ErrorResponse.class));
+        try {
+            executeEngine.execute();
+        } catch (final SQLException ex) {
+            assertThat(ex.getMessage(), is("No Registry center to execute `DropDatabaseStatementContext` SQL"));
+        }
         setGovernanceSchemaContexts(true);
-        response = executeEngine.execute();
+        BackendResponse response = executeEngine.execute();
         assertThat(response, instanceOf(UpdateResponse.class));
     }
     
     @Test
-    public void assertExecuteCreateDatabaseContextWithException() {
+    public void assertExecuteCreateDatabaseContextWithException() throws SQLException {
         BackendConnection connection = mock(BackendConnection.class);
         when(connection.getSchema()).thenReturn("schema");
         RDLBackendHandler executeEngine = new RDLBackendHandler(connection, new CreateDatabaseStatement("schema"));
-        BackendResponse response = executeEngine.execute();
-        assertThat(response, instanceOf(ErrorResponse.class));
+        try {
+            executeEngine.execute();
+        } catch (final SQLException ex) {
+            assertThat(ex.getMessage(), is("No Registry center to execute `CreateDatabaseStatementContext` SQL"));
+        }
         setGovernanceSchemaContexts(true);
-        response = executeEngine.execute();
-        assertThat(response, instanceOf(ErrorResponse.class));
-        assertThat(((ErrorResponse) response).getCause(), instanceOf(DBCreateExistsException.class));
+        try {
+            executeEngine.execute();
+        } catch (final DBCreateExistsException ex) {
+            assertNull(ex.getMessage());
+        }
     }
     
     private Map<String, SchemaContext> getSchemaContextMap() {
@@ -102,26 +115,32 @@ public final class RDLBackendHandlerTest {
     }
     
     @Test
-    public void assertExecuteDataSourcesContext() {
+    public void assertExecuteDataSourcesContext() throws SQLException {
         BackendConnection connection = mock(BackendConnection.class);
         when(connection.getSchema()).thenReturn("schema");
         RDLBackendHandler executeEngine = new RDLBackendHandler(connection, mock(CreateDataSourcesStatement.class));
-        BackendResponse response = executeEngine.execute();
-        assertThat(response, instanceOf(ErrorResponse.class));
+        try {
+            executeEngine.execute();
+        } catch (final SQLException ex) {
+            assertThat(ex.getMessage(), is("No Registry center to execute `CreateDataSourcesStatementContext` SQL"));
+        }
         setGovernanceSchemaContexts(true);
-        response = executeEngine.execute();
+        BackendResponse response = executeEngine.execute();
         assertThat(response, instanceOf(UpdateResponse.class));
     }
     
     @Test
-    public void assertExecuteShardingRuleContext() {
+    public void assertExecuteShardingRuleContext() throws SQLException {
         BackendConnection connection = mock(BackendConnection.class);
         when(connection.getSchema()).thenReturn("schema");
         RDLBackendHandler executeEngine = new RDLBackendHandler(connection, mock(CreateShardingRuleStatement.class));
-        BackendResponse response = executeEngine.execute();
-        assertThat(response, instanceOf(ErrorResponse.class));
+        try {
+            executeEngine.execute();
+        } catch (final SQLException ex) {
+            assertThat(ex.getMessage(), is("No Registry center to execute `CreateShardingRuleStatementContext` SQL"));
+        }
         setGovernanceSchemaContexts(true);
-        response = executeEngine.execute();
+        BackendResponse response = executeEngine.execute();
         assertThat(response, instanceOf(UpdateResponse.class));
     }
     

shardingsphere-proxy/shardingsphere-proxy-backend/src/test/java/org/apache/shardingsphere/proxy/backend/text/admin/ShowTablesBackendHandlerTest.java

@@ -83,7 +83,7 @@ public class ShowTablesBackendHandlerTest {
     }
     
     @Test
-    public void assertExecuteShowTablesBackendHandler() {
+    public void assertExecuteShowTablesBackendHandler() throws SQLException {
         QueryResponse actual = (QueryResponse) tablesBackendHandler.execute();
         assertThat(actual, instanceOf(QueryResponse.class));
         assertThat(actual.getQueryHeaders().size(), is(1));

shardingsphere-proxy/shardingsphere-proxy-backend/src/test/java/org/apache/shardingsphere/proxy/backend/text/admin/UnicastBackendHandlerTest.java

@@ -39,6 +39,7 @@ import org.mockito.Spy;
 import org.mockito.junit.MockitoJUnitRunner;
 
 import java.lang.reflect.Field;
+import java.sql.SQLException;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Properties;
@@ -62,8 +63,7 @@ public final class UnicastBackendHandlerTest {
     private DatabaseCommunicationEngineFactory databaseCommunicationEngineFactory;
     
     @Before
-    @SneakyThrows(ReflectiveOperationException.class)
-    public void setUp() {
+    public void setUp() throws SQLException, IllegalAccessException, NoSuchFieldException {
         Field schemaContexts = ProxyContext.getInstance().getClass().getDeclaredField("schemaContexts");
         schemaContexts.setAccessible(true);
         schemaContexts.set(ProxyContext.getInstance(),
@@ -80,7 +80,7 @@ public final class UnicastBackendHandlerTest {
     }
     
     @Test
-    public void assertExecuteWhileSchemaIsNull() {
+    public void assertExecuteWhileSchemaIsNull() throws SQLException {
         UnicastBackendHandler backendHandler = new UnicastBackendHandler("show variable like %s", mock(SQLStatement.class), backendConnection);
         backendConnection.setCurrentSchema(String.format(SCHEMA_PATTERN, 8));
         setDatabaseCommunicationEngine(backendHandler);
@@ -90,7 +90,7 @@ public final class UnicastBackendHandlerTest {
     }
     
     @Test
-    public void assertExecuteWhileSchemaNotNull() {
+    public void assertExecuteWhileSchemaNotNull() throws SQLException {
         backendConnection.setCurrentSchema(String.format(SCHEMA_PATTERN, 0));
         UnicastBackendHandler backendHandler = new UnicastBackendHandler("show variable like %s", mock(SQLStatement.class), backendConnection);
         setDatabaseCommunicationEngine(backendHandler);
@@ -99,7 +99,7 @@ public final class UnicastBackendHandlerTest {
         backendHandler.execute();
     }
     
-    private void setUnderlyingHandler(final BackendResponse backendResponse) {
+    private void setUnderlyingHandler(final BackendResponse backendResponse) throws SQLException {
         DatabaseCommunicationEngine databaseCommunicationEngine = mock(DatabaseCommunicationEngine.class);
         when(databaseCommunicationEngine.execute()).thenReturn(backendResponse);
         when(databaseCommunicationEngineFactory.newTextProtocolInstance(any(), anyString(), any())).thenReturn(databaseCommunicationEngine);

shardingsphere-proxy/shardingsphere-proxy-backend/src/test/java/org/apache/shardingsphere/proxy/backend/text/admin/UseDatabaseBackendHandlerTest.java

@@ -17,7 +17,6 @@
 
 package org.apache.shardingsphere.proxy.backend.text.admin;
 
-import lombok.SneakyThrows;
 import org.apache.shardingsphere.infra.auth.Authentication;
 import org.apache.shardingsphere.infra.auth.ProxyUser;
 import org.apache.shardingsphere.infra.config.properties.ConfigurationProperties;
@@ -25,10 +24,10 @@ import org.apache.shardingsphere.infra.context.SchemaContext;
 import org.apache.shardingsphere.infra.context.impl.StandardSchemaContexts;
 import org.apache.shardingsphere.infra.database.type.dialect.MySQLDatabaseType;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
+import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
+import org.apache.shardingsphere.proxy.backend.exception.UnknownDatabaseException;
 import org.apache.shardingsphere.proxy.backend.response.BackendResponse;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
 import org.apache.shardingsphere.proxy.backend.response.update.UpdateResponse;
-import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.sql.parser.sql.dialect.statement.mysql.dal.MySQLUseStatement;
 import org.junit.Before;
 import org.junit.Test;
@@ -45,7 +44,6 @@ import static org.hamcrest.CoreMatchers.instanceOf;
 import static org.junit.Assert.assertThat;
 import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
@@ -57,8 +55,7 @@ public final class UseDatabaseBackendHandlerTest {
     private BackendConnection backendConnection;
     
     @Before
-    @SneakyThrows(ReflectiveOperationException.class)
-    public void setUp() {
+    public void setUp() throws NoSuchFieldException, IllegalAccessException {
         backendConnection = mock(BackendConnection.class);
         when(backendConnection.getUsername()).thenReturn("root");
         Field schemaContexts = ProxyContext.getInstance().getClass().getDeclaredField("schemaContexts");
@@ -92,13 +89,11 @@ public final class UseDatabaseBackendHandlerTest {
         assertThat(actual, instanceOf(UpdateResponse.class));
     }
     
-    @Test
+    @Test(expected = UnknownDatabaseException.class)
     public void assertExecuteUseStatementNotExist() {
         MySQLUseStatement useStatement = mock(MySQLUseStatement.class);
         when(useStatement.getSchema()).thenReturn("not_exist");
         UseDatabaseBackendHandler useSchemaBackendHandler = new UseDatabaseBackendHandler(useStatement, backendConnection);
-        BackendResponse actual = useSchemaBackendHandler.execute();
-        assertThat(actual, instanceOf(ErrorResponse.class));
-        verify(backendConnection, times(0)).setCurrentSchema(anyString());
+        useSchemaBackendHandler.execute();
     }
 }

shardingsphere-proxy/shardingsphere-proxy-backend/src/test/java/org/apache/shardingsphere/proxy/backend/text/sctl/hint/ShardingCTLHintBackendHandlerTest.java

@@ -30,12 +30,11 @@ import org.apache.shardingsphere.infra.metadata.ShardingSphereMetaData;
 import org.apache.shardingsphere.infra.metadata.datasource.DataSourceMetaDatas;
 import org.apache.shardingsphere.infra.metadata.schema.RuleSchemaMetaData;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
+import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.backend.response.BackendResponse;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryData;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryResponse;
 import org.apache.shardingsphere.proxy.backend.response.update.UpdateResponse;
-import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.backend.text.sctl.exception.InvalidShardingCTLFormatException;
 import org.apache.shardingsphere.proxy.backend.text.sctl.exception.UnsupportedShardingCTLTypeException;
 import org.apache.shardingsphere.proxy.backend.text.sctl.hint.internal.HintManagerHolder;
@@ -79,12 +78,11 @@ public final class ShardingCTLHintBackendHandlerTest {
         new ShardingCTLHintBackendHandler("", backendConnection).execute();
     }
     
-    @Test
+    @Test(expected = InvalidShardingCTLFormatException.class)
     public void assertInvalidShardingCTLFormat() {
         clearThreadLocal();
         String sql = "sctl:hint1 xx=yy";
-        ShardingCTLHintBackendHandler shardingCTLHintBackendHandler = new ShardingCTLHintBackendHandler(sql, backendConnection);
-        assertThat(((ErrorResponse) shardingCTLHintBackendHandler.execute()).getCause(), instanceOf(InvalidShardingCTLFormatException.class));
+        new ShardingCTLHintBackendHandler(sql, backendConnection).execute();
     }
     
     private void clearThreadLocal() {
@@ -214,11 +212,10 @@ public final class ShardingCTLHintBackendHandlerTest {
         return Collections.singletonMap("schema", result);
     }
     
-    @Test
+    @Test(expected = UnsupportedShardingCTLTypeException.class)
     public void assertUnsupportedShardingCTLType() {
         clearThreadLocal();
         String sql = "sctl:hint xx=yy";
-        ShardingCTLHintBackendHandler shardingCTLHintBackendHandler = new ShardingCTLHintBackendHandler(sql, backendConnection);
-        assertThat(((ErrorResponse) shardingCTLHintBackendHandler.execute()).getCause(), instanceOf(UnsupportedShardingCTLTypeException.class));
+        new ShardingCTLHintBackendHandler(sql, backendConnection).execute();
     }
 }

shardingsphere-proxy/shardingsphere-proxy-backend/src/test/java/org/apache/shardingsphere/proxy/backend/text/sctl/set/ShardingCTLSetBackendHandlerTest.java

@@ -24,10 +24,11 @@ import org.apache.shardingsphere.infra.context.SchemaContext;
 import org.apache.shardingsphere.infra.context.impl.StandardSchemaContexts;
 import org.apache.shardingsphere.infra.database.type.dialect.MySQLDatabaseType;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
+import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.backend.response.BackendResponse;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
 import org.apache.shardingsphere.proxy.backend.response.update.UpdateResponse;
-import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
+import org.apache.shardingsphere.proxy.backend.text.sctl.exception.InvalidShardingCTLFormatException;
+import org.apache.shardingsphere.proxy.backend.text.sctl.exception.UnsupportedShardingCTLTypeException;
 import org.apache.shardingsphere.transaction.core.TransactionType;
 import org.junit.Before;
 import org.junit.Test;
@@ -92,26 +93,19 @@ public final class ShardingCTLSetBackendHandlerTest {
         assertThat(backendConnection.getTransactionType(), is(TransactionType.LOCAL));
     }
     
-    @Test
+    @Test(expected = UnsupportedShardingCTLTypeException.class)
     public void assertSwitchTransactionTypeFailed() {
         backendConnection.setCurrentSchema(String.format(SCHEMA_PATTERN, 0));
-        ShardingCTLSetBackendHandler shardingCTLBackendHandler = new ShardingCTLSetBackendHandler("sctl:set transaction_type=XXX", backendConnection);
-        BackendResponse actual = shardingCTLBackendHandler.execute();
-        assertThat(actual, instanceOf(ErrorResponse.class));
-        assertThat(backendConnection.getTransactionType(), is(TransactionType.LOCAL));
+        new ShardingCTLSetBackendHandler("sctl:set transaction_type=XXX", backendConnection).execute();
     }
     
-    @Test
+    @Test(expected = UnsupportedShardingCTLTypeException.class)
     public void assertNotSupportedSCTL() {
-        ShardingCTLSetBackendHandler shardingCTLBackendHandler = new ShardingCTLSetBackendHandler("sctl:set @@session=XXX", backendConnection);
-        BackendResponse actual = shardingCTLBackendHandler.execute();
-        assertThat(actual, instanceOf(ErrorResponse.class));
+        new ShardingCTLSetBackendHandler("sctl:set @@session=XXX", backendConnection).execute();
     }
     
-    @Test
+    @Test(expected = InvalidShardingCTLFormatException.class)
     public void assertFormatErrorSCTL() {
-        ShardingCTLSetBackendHandler shardingCTLBackendHandler = new ShardingCTLSetBackendHandler("sctl:set yyyyy", backendConnection);
-        BackendResponse actual = shardingCTLBackendHandler.execute();
-        assertThat(actual, instanceOf(ErrorResponse.class));
+        new ShardingCTLSetBackendHandler("sctl:set yyyyy", backendConnection).execute();
     }
 }

shardingsphere-proxy/shardingsphere-proxy-backend/src/test/java/org/apache/shardingsphere/proxy/backend/text/sctl/show/ShardingCTLShowBackendHandlerTest.java

@@ -19,7 +19,6 @@ package org.apache.shardingsphere.proxy.backend.text.sctl.show;
 
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
 import org.apache.shardingsphere.proxy.backend.response.BackendResponse;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryData;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryResponse;
 import org.apache.shardingsphere.proxy.backend.text.sctl.exception.InvalidShardingCTLFormatException;
@@ -61,21 +60,15 @@ public final class ShardingCTLShowBackendHandlerTest {
         assertThat(queryData.getData().iterator().next(), is(0));
     }
     
-    @Test
+    @Test(expected = UnsupportedShardingCTLTypeException.class)
     public void assertShowCachedConnectionFailed() {
         backendConnection.setCurrentSchema("schema");
-        ShardingCTLShowBackendHandler backendHandler = new ShardingCTLShowBackendHandler("sctl:show cached_connectionss", backendConnection);
-        BackendResponse actual = backendHandler.execute();
-        assertThat(actual, instanceOf(ErrorResponse.class));
-        assertThat(((ErrorResponse) actual).getCause(), instanceOf(UnsupportedShardingCTLTypeException.class));
+        new ShardingCTLShowBackendHandler("sctl:show cached_connectionss", backendConnection).execute();
     }
     
-    @Test
+    @Test(expected = InvalidShardingCTLFormatException.class)
     public void assertShowCTLFormatError() {
         backendConnection.setCurrentSchema("schema");
-        ShardingCTLShowBackendHandler backendHandler = new ShardingCTLShowBackendHandler("sctl:show=xx", backendConnection);
-        BackendResponse actual = backendHandler.execute();
-        assertThat(actual, instanceOf(ErrorResponse.class));
-        assertThat(((ErrorResponse) actual).getCause(), instanceOf(InvalidShardingCTLFormatException.class));
+        new ShardingCTLShowBackendHandler("sctl:show=xx", backendConnection).execute();
     }
 }

shardingsphere-proxy/shardingsphere-proxy-backend/src/test/java/org/apache/shardingsphere/proxy/backend/text/transaction/TransactionBackendHandlerTest.java

@@ -26,6 +26,8 @@ import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.junit.MockitoJUnitRunner;
 
+import java.sql.SQLException;
+
 import static org.hamcrest.CoreMatchers.instanceOf;
 import static org.junit.Assert.assertThat;
 
@@ -35,7 +37,7 @@ public final class TransactionBackendHandlerTest {
     private final BackendConnection backendConnection = new BackendConnection(TransactionType.LOCAL);
     
     @Test
-    public void assertExecute() {
+    public void assertExecute() throws SQLException {
         TransactionBackendHandler transactionBackendHandler = new TransactionBackendHandler(TransactionOperationType.BEGIN, backendConnection);
         BackendResponse actual = transactionBackendHandler.execute();
         assertThat(actual, instanceOf(UpdateResponse.class));

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-mysql/src/main/java/org/apache/shardingsphere/proxy/frontend/mysql/command/query/binary/execute/MySQLComStmtExecuteExecutor.java

@@ -35,13 +35,11 @@ import org.apache.shardingsphere.proxy.backend.communication.DatabaseCommunicati
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
 import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.backend.response.BackendResponse;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryData;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryResponse;
 import org.apache.shardingsphere.proxy.backend.response.update.UpdateResponse;
 import org.apache.shardingsphere.proxy.frontend.command.executor.QueryCommandExecutor;
 import org.apache.shardingsphere.proxy.frontend.command.executor.ResponseType;
-import org.apache.shardingsphere.proxy.frontend.mysql.MySQLErrPacketFactory;
 import org.apache.shardingsphere.sql.parser.sql.common.statement.SQLStatement;
 
 import java.sql.SQLException;
@@ -65,36 +63,22 @@ public final class MySQLComStmtExecuteExecutor implements QueryCommandExecutor {
     
     public MySQLComStmtExecuteExecutor(final MySQLComStmtExecutePacket comStmtExecutePacket, final BackendConnection backendConnection) {
         SQLStatement sqlStatement = ProxyContext.getInstance().getSchema(backendConnection.getSchema()).getRuntimeContext().getSqlParserEngine().parse(comStmtExecutePacket.getSql(), true);
-        databaseCommunicationEngine = DatabaseCommunicationEngineFactory.getInstance().newBinaryProtocolInstance(sqlStatement,
-                comStmtExecutePacket.getSql(), comStmtExecutePacket.getParameters(), backendConnection);
+        databaseCommunicationEngine = DatabaseCommunicationEngineFactory.getInstance().newBinaryProtocolInstance(
+                sqlStatement, comStmtExecutePacket.getSql(), comStmtExecutePacket.getParameters(), backendConnection);
     }
     
     @Override
-    public Collection<DatabasePacket<?>> execute() {
+    public Collection<DatabasePacket<?>> execute() throws SQLException {
         if (ProxyContext.getInstance().getSchemaContexts().isCircuitBreak()) {
             return Collections.singletonList(new MySQLErrPacket(1, CommonErrorCode.CIRCUIT_BREAK_MODE));
         }
-        BackendResponse backendResponse = getBackendResponse();
+        BackendResponse backendResponse = databaseCommunicationEngine.execute();
         if (backendResponse instanceof QueryResponse) {
             responseType = ResponseType.QUERY;
             return createQueryPacket((QueryResponse) backendResponse);
         }
-        if (backendResponse instanceof UpdateResponse) {
-            responseType = ResponseType.UPDATE;
-            return Collections.singletonList(createUpdatePacket((UpdateResponse) backendResponse));
-        }
-        responseType = ResponseType.ERROR;
-        return Collections.singletonList(createErrorPacket(((ErrorResponse) backendResponse).getCause()));
-    }
-    
-    private BackendResponse getBackendResponse() {
-        try {
-            return databaseCommunicationEngine.execute();
-        // CHECKSTYLE:OFF
-        } catch (final Exception ex) {
-        // CHECKSTYLE:OFF
-            return new ErrorResponse(ex);
-        }
+        responseType = ResponseType.UPDATE;
+        return Collections.singletonList(createUpdatePacket((UpdateResponse) backendResponse));
     }
     
     private Collection<DatabasePacket<?>> createQueryPacket(final QueryResponse backendResponse) {
@@ -113,10 +97,6 @@ public final class MySQLComStmtExecuteExecutor implements QueryCommandExecutor {
         return new MySQLOKPacket(1, updateResponse.getUpdateCount(), updateResponse.getLastInsertId());
     }
     
-    private MySQLErrPacket createErrorPacket(final Exception cause) {
-        return MySQLErrPacketFactory.newInstance(1, cause);
-    }
-    
     @Override
     public boolean next() throws SQLException {
         return databaseCommunicationEngine.next();

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-mysql/src/main/java/org/apache/shardingsphere/proxy/frontend/mysql/command/query/text/fieldlist/MySQLComFieldListPacketExecutor.java

@@ -25,18 +25,13 @@ import org.apache.shardingsphere.db.protocol.packet.DatabasePacket;
 import org.apache.shardingsphere.proxy.backend.communication.DatabaseCommunicationEngine;
 import org.apache.shardingsphere.proxy.backend.communication.DatabaseCommunicationEngineFactory;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
-import org.apache.shardingsphere.proxy.backend.response.BackendResponse;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
 import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.frontend.command.executor.CommandExecutor;
-import org.apache.shardingsphere.proxy.frontend.mysql.MySQLErrPacketFactory;
 import org.apache.shardingsphere.sql.parser.sql.common.statement.SQLStatement;
 
 import java.sql.SQLException;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.LinkedList;
-import java.util.List;
 
 /**
  * COM_FIELD_LIST packet executor for MySQL.
@@ -63,12 +58,8 @@ public final class MySQLComFieldListPacketExecutor implements CommandExecutor {
     
     @Override
     public Collection<DatabasePacket<?>> execute() throws SQLException {
-        BackendResponse backendResponse = databaseCommunicationEngine.execute();
-        return backendResponse instanceof ErrorResponse ? createErrorPackets((ErrorResponse) backendResponse) : createColumnDefinition41Packets();
-    }
-    
-    private List<DatabasePacket<?>> createErrorPackets(final ErrorResponse backendResponse) {
-        return Collections.singletonList(MySQLErrPacketFactory.newInstance(1, backendResponse.getCause()));
+        databaseCommunicationEngine.execute();
+        return createColumnDefinition41Packets();
     }
     
     private Collection<DatabasePacket<?>> createColumnDefinition41Packets() throws SQLException {

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-mysql/src/main/java/org/apache/shardingsphere/proxy/frontend/mysql/command/query/text/query/MySQLComQueryPacketExecutor.java

@@ -35,14 +35,12 @@ import org.apache.shardingsphere.infra.executor.sql.raw.execute.result.query.Que
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
 import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.backend.response.BackendResponse;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryResponse;
 import org.apache.shardingsphere.proxy.backend.response.update.UpdateResponse;
 import org.apache.shardingsphere.proxy.backend.text.TextProtocolBackendHandler;
 import org.apache.shardingsphere.proxy.backend.text.TextProtocolBackendHandlerFactory;
 import org.apache.shardingsphere.proxy.frontend.command.executor.QueryCommandExecutor;
 import org.apache.shardingsphere.proxy.frontend.command.executor.ResponseType;
-import org.apache.shardingsphere.proxy.frontend.mysql.MySQLErrPacketFactory;
 
 import java.sql.SQLException;
 import java.util.Collection;
@@ -67,31 +65,17 @@ public final class MySQLComQueryPacketExecutor implements QueryCommandExecutor {
     }
     
     @Override
-    public Collection<DatabasePacket<?>> execute() {
+    public Collection<DatabasePacket<?>> execute() throws SQLException {
         if (ProxyContext.getInstance().getSchemaContexts().isCircuitBreak()) {
             return Collections.singletonList(new MySQLErrPacket(1, CommonErrorCode.CIRCUIT_BREAK_MODE));
         }
-        BackendResponse backendResponse = getBackendResponse();
+        BackendResponse backendResponse = textProtocolBackendHandler.execute();
         if (backendResponse instanceof QueryResponse) {
             responseType = ResponseType.QUERY;
             return createQueryPackets((QueryResponse) backendResponse);
         }
-        if (backendResponse instanceof UpdateResponse) {
-            responseType = ResponseType.UPDATE;
-            return Collections.singletonList(createUpdatePacket((UpdateResponse) backendResponse));
-        }
-        responseType = ResponseType.ERROR;
-        return Collections.singletonList(createErrorPacket(((ErrorResponse) backendResponse).getCause()));
-    }
-    
-    private BackendResponse getBackendResponse() {
-        try {
-            return textProtocolBackendHandler.execute();
-        // CHECKSTYLE:OFF
-        } catch (final Exception ex) {
-        // CHECKSTYLE:OFF
-            return new ErrorResponse(ex);
-        }
+        responseType = ResponseType.UPDATE;
+        return Collections.singletonList(createUpdatePacket((UpdateResponse) backendResponse));
     }
     
     private Collection<DatabasePacket<?>> createQueryPackets(final QueryResponse backendResponse) {
@@ -127,10 +111,6 @@ public final class MySQLComQueryPacketExecutor implements QueryCommandExecutor {
         return new MySQLOKPacket(1, updateResponse.getUpdateCount(), updateResponse.getLastInsertId());
     }
     
-    private MySQLErrPacket createErrorPacket(final Exception cause) {
-        return MySQLErrPacketFactory.newInstance(1, cause);
-    }
-    
     @Override
     public boolean next() throws SQLException {
         return textProtocolBackendHandler.next();

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-mysql/src/test/java/org/apache/shardingsphere/proxy/frontend/mysql/command/query/binary/execute/MySQLComStmtExecuteExecutorTest.java

@@ -27,10 +27,9 @@ import org.apache.shardingsphere.infra.database.type.dialect.MySQLDatabaseType;
 import org.apache.shardingsphere.infra.executor.sql.raw.execute.result.query.QueryHeader;
 import org.apache.shardingsphere.proxy.backend.communication.DatabaseCommunicationEngine;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
+import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryResponse;
 import org.apache.shardingsphere.proxy.backend.response.update.UpdateResponse;
-import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.frontend.command.executor.ResponseType;
 import org.apache.shardingsphere.rdl.parser.engine.ShardingSphereSQLParserEngine;
 import org.junit.Before;
@@ -54,9 +53,6 @@ import static org.mockito.Mockito.when;
 @RunWith(MockitoJUnitRunner.class)
 public final class MySQLComStmtExecuteExecutorTest {
     
-    @Mock
-    private SQLException sqlException;
-    
     @Mock
     private DatabaseCommunicationEngine databaseCommunicationEngine;
     
@@ -78,7 +74,7 @@ public final class MySQLComStmtExecuteExecutorTest {
     }
     
     @Test
-    public void assertIsQueryResponse() throws NoSuchFieldException {
+    public void assertIsQueryResponse() throws NoSuchFieldException, SQLException {
         BackendConnection backendConnection = mock(BackendConnection.class);
         when(backendConnection.getSchema()).thenReturn("schema");
         MySQLComStmtExecuteExecutor mysqlComStmtExecuteExecutor = new MySQLComStmtExecuteExecutor(mock(MySQLComStmtExecutePacket.class), backendConnection);
@@ -89,7 +85,7 @@ public final class MySQLComStmtExecuteExecutorTest {
     }
     
     @Test
-    public void assertIsUpdateResponse() throws NoSuchFieldException {
+    public void assertIsUpdateResponse() throws NoSuchFieldException, SQLException {
         BackendConnection backendConnection = mock(BackendConnection.class);
         when(backendConnection.getSchema()).thenReturn("schema");
         MySQLComStmtExecuteExecutor mysqlComStmtExecuteExecutor = new MySQLComStmtExecuteExecutor(mock(MySQLComStmtExecutePacket.class), backendConnection);
@@ -98,15 +94,4 @@ public final class MySQLComStmtExecuteExecutorTest {
         mysqlComStmtExecuteExecutor.execute();
         assertThat(mysqlComStmtExecuteExecutor.getResponseType(), is(ResponseType.UPDATE));
     }
-    
-    @Test
-    public void assertIsErrorResponse() throws NoSuchFieldException {
-        BackendConnection backendConnection = mock(BackendConnection.class);
-        when(backendConnection.getSchema()).thenReturn("schema");
-        MySQLComStmtExecuteExecutor mysqlComStmtExecuteExecutor = new MySQLComStmtExecuteExecutor(mock(MySQLComStmtExecutePacket.class), backendConnection);
-        FieldSetter.setField(mysqlComStmtExecuteExecutor, MySQLComStmtExecuteExecutor.class.getDeclaredField("databaseCommunicationEngine"), databaseCommunicationEngine);
-        when(databaseCommunicationEngine.execute()).thenReturn(new ErrorResponse(sqlException));
-        mysqlComStmtExecuteExecutor.execute();
-        assertThat(mysqlComStmtExecuteExecutor.getResponseType(), is(ResponseType.ERROR));
-    }
 }

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-mysql/src/test/java/org/apache/shardingsphere/proxy/frontend/mysql/command/query/text/query/MySQLComQueryPacketExecutorTest.java

@@ -19,7 +19,6 @@ package org.apache.shardingsphere.proxy.frontend.mysql.command.query.text.query;
 
 import org.apache.shardingsphere.db.protocol.mysql.packet.command.query.text.query.MySQLComQueryPacket;
 import org.apache.shardingsphere.infra.executor.sql.raw.execute.result.query.QueryHeader;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryResponse;
 import org.apache.shardingsphere.proxy.backend.response.update.UpdateResponse;
 import org.apache.shardingsphere.proxy.backend.text.TextProtocolBackendHandler;
@@ -41,9 +40,6 @@ import static org.mockito.Mockito.when;
 @RunWith(MockitoJUnitRunner.class)
 public final class MySQLComQueryPacketExecutorTest {
     
-    @Mock
-    private SQLException sqlException;
-    
     @Mock
     private TextProtocolBackendHandler textProtocolBackendHandler;
     
@@ -64,12 +60,4 @@ public final class MySQLComQueryPacketExecutorTest {
         mysqlComQueryPacketExecutor.execute();
         assertThat(mysqlComQueryPacketExecutor.getResponseType(), is(ResponseType.UPDATE));
     }
-    
-    @Test
-    public void assertIsErrorResponse() throws SQLException, NoSuchFieldException {
-        FieldSetter.setField(mysqlComQueryPacketExecutor, MySQLComQueryPacketExecutor.class.getDeclaredField("textProtocolBackendHandler"), textProtocolBackendHandler);
-        when(textProtocolBackendHandler.execute()).thenReturn(new ErrorResponse(sqlException));
-        mysqlComQueryPacketExecutor.execute();
-        assertThat(mysqlComQueryPacketExecutor.getResponseType(), is(ResponseType.ERROR));
-    }
 }

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-postgresql/src/main/java/org/apache/shardingsphere/proxy/frontend/postgresql/command/PostgreSQLCommandExecuteEngine.java

@@ -83,7 +83,7 @@ public final class PostgreSQLCommandExecuteEngine implements CommandExecuteEngin
             context.write(new PostgreSQLReadyForQueryPacket());
             return;
         }
-        if (ResponseType.ERROR == queryCommandExecutor.getResponseType() || ResponseType.UPDATE == queryCommandExecutor.getResponseType()) {
+        if (ResponseType.UPDATE == queryCommandExecutor.getResponseType()) {
             context.write(new PostgreSQLReadyForQueryPacket());
             return;
         }

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-postgresql/src/main/java/org/apache/shardingsphere/proxy/frontend/postgresql/command/query/binary/bind/PostgreSQLComBindExecutor.java

@@ -37,13 +37,11 @@ import org.apache.shardingsphere.proxy.backend.communication.DatabaseCommunicati
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
 import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.backend.response.BackendResponse;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryData;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryResponse;
 import org.apache.shardingsphere.proxy.backend.response.update.UpdateResponse;
 import org.apache.shardingsphere.proxy.frontend.command.executor.QueryCommandExecutor;
 import org.apache.shardingsphere.proxy.frontend.command.executor.ResponseType;
-import org.apache.shardingsphere.proxy.frontend.postgresql.PostgreSQLErrPacketFactory;
 import org.apache.shardingsphere.sql.parser.sql.common.statement.SQLStatement;
 
 import java.sql.ResultSetMetaData;
@@ -80,7 +78,7 @@ public final class PostgreSQLComBindExecutor implements QueryCommandExecutor {
     }
     
     @Override
-    public Collection<DatabasePacket<?>> execute() {
+    public Collection<DatabasePacket<?>> execute() throws SQLException {
         if (ProxyContext.getInstance().getSchemaContexts().isCircuitBreak()) {
             return Collections.singletonList(new PostgreSQLErrorResponsePacket());
         }
@@ -89,7 +87,7 @@ public final class PostgreSQLComBindExecutor implements QueryCommandExecutor {
         if (null == databaseCommunicationEngine) {
             return result;
         }
-        BackendResponse backendResponse = getBackendResponse();
+        BackendResponse backendResponse = databaseCommunicationEngine.execute();
         if (backendResponse instanceof QueryResponse) {
             createQueryPacket((QueryResponse) backendResponse).ifPresent(result::add);
         }
@@ -97,22 +95,6 @@ public final class PostgreSQLComBindExecutor implements QueryCommandExecutor {
             responseType = ResponseType.UPDATE;
             result.add(createUpdatePacket((UpdateResponse) backendResponse));
         }
-        if (backendResponse instanceof ErrorResponse) {
-            responseType = ResponseType.ERROR;
-            result.add(createErrorPacket((ErrorResponse) backendResponse));
-        }
-        return result;
-    }
-    
-    private BackendResponse getBackendResponse() {
-        BackendResponse result;
-        try {
-            result = databaseCommunicationEngine.execute();
-        // CHECKSTYLE:OFF
-        } catch (final Exception ex) {
-        // CHECKSTYLE:OFF
-            result = new ErrorResponse(ex);
-        }
         return result;
     }
     
@@ -142,10 +124,6 @@ public final class PostgreSQLComBindExecutor implements QueryCommandExecutor {
         return new PostgreSQLCommandCompletePacket(updateResponse.getType(), updateResponse.getUpdateCount());
     }
     
-    private PostgreSQLErrorResponsePacket createErrorPacket(final ErrorResponse errorResponse) {
-        return PostgreSQLErrPacketFactory.newInstance(errorResponse.getCause());
-    }
-    
     @Override
     public boolean next() throws SQLException {
         return null != databaseCommunicationEngine && databaseCommunicationEngine.next();

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-postgresql/src/main/java/org/apache/shardingsphere/proxy/frontend/postgresql/command/query/text/PostgreSQLComQueryExecutor.java

@@ -32,14 +32,12 @@ import org.apache.shardingsphere.infra.executor.sql.raw.execute.result.query.Que
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
 import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.backend.response.BackendResponse;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
 import org.apache.shardingsphere.proxy.backend.response.query.QueryResponse;
 import org.apache.shardingsphere.proxy.backend.response.update.UpdateResponse;
 import org.apache.shardingsphere.proxy.backend.text.TextProtocolBackendHandler;
 import org.apache.shardingsphere.proxy.backend.text.TextProtocolBackendHandlerFactory;
 import org.apache.shardingsphere.proxy.frontend.command.executor.QueryCommandExecutor;
 import org.apache.shardingsphere.proxy.frontend.command.executor.ResponseType;
-import org.apache.shardingsphere.proxy.frontend.postgresql.PostgreSQLErrPacketFactory;
 
 import java.sql.ResultSetMetaData;
 import java.sql.SQLException;
@@ -64,33 +62,17 @@ public final class PostgreSQLComQueryExecutor implements QueryCommandExecutor {
     }
     
     @Override
-    public Collection<DatabasePacket<?>> execute() {
+    public Collection<DatabasePacket<?>> execute() throws SQLException {
         if (ProxyContext.getInstance().getSchemaContexts().isCircuitBreak()) {
             return Collections.singletonList(new PostgreSQLErrorResponsePacket());
         }
-        BackendResponse backendResponse = getBackendResponse();
+        BackendResponse backendResponse = textProtocolBackendHandler.execute();
         if (backendResponse instanceof QueryResponse) {
             Optional<PostgreSQLRowDescriptionPacket> result = createQueryPacket((QueryResponse) backendResponse);
             return result.<List<DatabasePacket<?>>>map(Collections::singletonList).orElseGet(Collections::emptyList);
         }
-        if (backendResponse instanceof UpdateResponse) {
-            responseType = ResponseType.UPDATE;
-            return Collections.singletonList(createUpdatePacket((UpdateResponse) backendResponse));
-        }
-        responseType = ResponseType.ERROR;
-        return Collections.singletonList(createErrorPacket((ErrorResponse) backendResponse));
-    }
-    
-    private BackendResponse getBackendResponse() {
-        BackendResponse result;
-        try {
-            result = textProtocolBackendHandler.execute();
-        // CHECKSTYLE:OFF
-        } catch (final Exception ex) {
-        // CHECKSTYLE:OFF
-            result = new ErrorResponse(ex);
-        }
-        return result;
+        responseType = ResponseType.UPDATE;
+        return Collections.singletonList(createUpdatePacket((UpdateResponse) backendResponse));
     }
     
     private Optional<PostgreSQLRowDescriptionPacket> createQueryPacket(final QueryResponse queryResponse) {
@@ -119,10 +101,6 @@ public final class PostgreSQLComQueryExecutor implements QueryCommandExecutor {
         return new PostgreSQLCommandCompletePacket(updateResponse.getType(), updateResponse.getUpdateCount());
     }
     
-    private PostgreSQLErrorResponsePacket createErrorPacket(final ErrorResponse errorResponse) {
-        return PostgreSQLErrPacketFactory.newInstance(errorResponse.getCause());
-    }
-    
     @Override
     public boolean next() throws SQLException {
         return textProtocolBackendHandler.next();

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-postgresql/src/test/java/org/apache/shardingsphere/proxy/frontend/postgresql/command/PostgreSQLCommandExecuteEngineTest.java

@@ -43,9 +43,9 @@ public final class PostgreSQLCommandExecuteEngineTest {
     
     @Test
     @SneakyThrows
-    public void assertWriteQueryDataWithError() {
+    public void assertWriteQueryDataWithUpdate() {
         PostgreSQLCommandExecuteEngine postgreSQLCommandExecuteEngine = new PostgreSQLCommandExecuteEngine();
-        when(queryCommandExecutor.getResponseType()).thenReturn(ResponseType.ERROR);
+        when(queryCommandExecutor.getResponseType()).thenReturn(ResponseType.UPDATE);
         postgreSQLCommandExecuteEngine.writeQueryData(channelHandlerContext, null, queryCommandExecutor, 0);
         verify(channelHandlerContext, times(1)).write(isA(PostgreSQLReadyForQueryPacket.class));
     }

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-postgresql/src/test/java/org/apache/shardingsphere/proxy/frontend/postgresql/command/query/binary/bind/PostgreSQLComBindExecutorTest.java

-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.shardingsphere.proxy.frontend.postgresql.command.query.binary.bind;
-
-import lombok.SneakyThrows;
-import org.apache.shardingsphere.db.protocol.postgresql.packet.command.query.binary.bind.PostgreSQLComBindPacket;
-import org.apache.shardingsphere.db.protocol.postgresql.packet.generic.PostgreSQLErrorResponsePacket;
-import org.apache.shardingsphere.infra.auth.Authentication;
-import org.apache.shardingsphere.infra.config.properties.ConfigurationProperties;
-import org.apache.shardingsphere.infra.context.SchemaContext;
-import org.apache.shardingsphere.infra.context.impl.StandardSchemaContexts;
-import org.apache.shardingsphere.infra.database.type.dialect.MySQLDatabaseType;
-import org.apache.shardingsphere.proxy.backend.communication.DatabaseCommunicationEngine;
-import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
-import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
-import org.apache.shardingsphere.proxy.frontend.command.executor.ResponseType;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.mockito.Mock;
-import org.mockito.internal.util.reflection.FieldSetter;
-import org.mockito.junit.MockitoJUnitRunner;
-import org.postgresql.util.PSQLException;
-import org.postgresql.util.ServerErrorMessage;
-
-import java.lang.reflect.Field;
-import java.util.Collections;
-import java.util.LinkedList;
-import java.util.Map;
-import java.util.Properties;
-
-import static org.hamcrest.CoreMatchers.instanceOf;
-import static org.hamcrest.CoreMatchers.is;
-import static org.junit.Assert.assertThat;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.when;
-
-@RunWith(MockitoJUnitRunner.class)
-public final class PostgreSQLComBindExecutorTest {
-    
-    @Mock
-    private DatabaseCommunicationEngine databaseCommunicationEngine;
-    
-    @Test
-    @SneakyThrows
-    public void assertExecuteHasError() {
-        Field schemaContexts = ProxyContext.getInstance().getClass().getDeclaredField("schemaContexts");
-        schemaContexts.setAccessible(true);
-        schemaContexts.set(ProxyContext.getInstance(),
-                new StandardSchemaContexts(getSchemaContextMap(), new Authentication(), new ConfigurationProperties(new Properties()), new MySQLDatabaseType()));
-        BackendConnection connection = mock(BackendConnection.class);
-        when(connection.getSchema()).thenReturn("schema");
-        PostgreSQLComBindExecutor postgreSQLComBindExecutor = new PostgreSQLComBindExecutor(mock(PostgreSQLComBindPacket.class), connection);
-        FieldSetter.setField(postgreSQLComBindExecutor, PostgreSQLComBindExecutor.class.getDeclaredField("databaseCommunicationEngine"), databaseCommunicationEngine);
-        ErrorResponse errorResponse = new ErrorResponse(new PSQLException(mock(ServerErrorMessage.class)));
-        when(databaseCommunicationEngine.execute()).thenReturn(errorResponse);
-        assertThat(((LinkedList) postgreSQLComBindExecutor.execute()).get(1), instanceOf(PostgreSQLErrorResponsePacket.class));
-        assertThat(postgreSQLComBindExecutor.getResponseType(), is(ResponseType.ERROR));
-    }
-    
-    private Map<String, SchemaContext> getSchemaContextMap() {
-        SchemaContext result = new SchemaContext("schema", null, null);
-        return Collections.singletonMap("schema", result);
-    }
-}

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-postgresql/src/test/java/org/apache/shardingsphere/proxy/frontend/postgresql/command/query/text/PostgreSQLComQueryExecutorTest.java

-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.shardingsphere.proxy.frontend.postgresql.command.query.text;
-
-import lombok.SneakyThrows;
-import org.apache.shardingsphere.db.protocol.postgresql.packet.command.query.text.PostgreSQLComQueryPacket;
-import org.apache.shardingsphere.db.protocol.postgresql.packet.generic.PostgreSQLErrorResponsePacket;
-import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
-import org.apache.shardingsphere.proxy.backend.text.TextProtocolBackendHandler;
-import org.apache.shardingsphere.proxy.frontend.command.executor.ResponseType;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.mockito.Mock;
-import org.mockito.internal.util.reflection.FieldSetter;
-import org.mockito.junit.MockitoJUnitRunner;
-import org.postgresql.util.PSQLException;
-import org.postgresql.util.ServerErrorMessage;
-
-import static org.hamcrest.CoreMatchers.instanceOf;
-import static org.hamcrest.CoreMatchers.is;
-import static org.junit.Assert.assertThat;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.when;
-
-@RunWith(MockitoJUnitRunner.class)
-public final class PostgreSQLComQueryExecutorTest {
-    
-    @Mock
-    private TextProtocolBackendHandler textProtocolBackendHandler;
-    
-    @Test
-    @SneakyThrows
-    public void assertExecuteReturnErrorResponsePacket() {
-        PostgreSQLComQueryExecutor postgreSQLComQueryExecutor = new PostgreSQLComQueryExecutor(mock(PostgreSQLComQueryPacket.class), null);
-        FieldSetter.setField(postgreSQLComQueryExecutor, PostgreSQLComQueryExecutor.class.getDeclaredField("textProtocolBackendHandler"), textProtocolBackendHandler);
-        ErrorResponse errorResponse = new ErrorResponse(new PSQLException(mock(ServerErrorMessage.class)));
-        when(textProtocolBackendHandler.execute()).thenReturn(errorResponse);
-        assertThat(postgreSQLComQueryExecutor.execute().iterator().next(), instanceOf(PostgreSQLErrorResponsePacket.class));
-        assertThat(postgreSQLComQueryExecutor.getResponseType(), is(ResponseType.ERROR));
-    }
-}

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-spi/src/main/java/org/apache/shardingsphere/proxy/frontend/command/executor/ResponseType.java

@@ -22,5 +22,5 @@ package org.apache.shardingsphere.proxy.frontend.command.executor;
  */
 public enum ResponseType {
     
-    QUERY, UPDATE, ERROR
+    QUERY, UPDATE
 }