fix for 5565

sharding-integration-test/sharding-jdbc-test/src/test/resources/integrate/cases/dql/dataset/dbtbl_with_masterslave/select_with_case_expression.xml

+<!--
+  ~ 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.
+  -->
+
+<dataset>
+    <metadata>
+        <column name="order_id" />
+        <column name="user_id" />
+        <column name="status" />
+        <column name="itemid" />
+        <column name="stateName" />
+    </metadata>
+    <row values="1000,10,init_slave,100000,null" />
+</dataset>

sharding-integration-test/sharding-jdbc-test/src/test/resources/integrate/cases/dql/dataset/masterslave/select_with_case_expression.xml

+<!--
+  ~ 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.
+  -->
+
+<dataset>
+    <metadata>
+        <column name="order_id" />
+        <column name="user_id" />
+        <column name="status" />
+        <column name="itemid" />
+        <column name="stateName" />
+    </metadata>
+    <row values="1000,10,init_slave,100001,null" />
+</dataset>

sharding-integration-test/sharding-jdbc-test/src/test/resources/integrate/cases/dql/dataset/shadow/select_with_case_expression.xml

+<!--
+  ~ 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.
+  -->
+
+<dataset>
+    <metadata>
+        <column name="order_id" />
+        <column name="user_id" />
+        <column name="status" />
+        <column name="itemid" />
+        <column name="stateName" />
+    </metadata>
+    <row values="1000,10,init,100001,已启用" />
+</dataset>

sharding-integration-test/sharding-jdbc-test/src/test/resources/integrate/cases/dql/dataset/tbl/select_with_case_expression.xml

+<!--
+  ~ 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.
+  -->
+
+<dataset>
+    <metadata>
+        <column name="order_id" />
+        <column name="user_id" />
+        <column name="status" />
+        <column name="itemid" />
+        <column name="stateName" />
+    </metadata>
+    <row values="1000,10,init,100000,已启用" />
+</dataset>

sharding-integration-test/sharding-jdbc-test/src/test/resources/integrate/cases/dql/dql-integrate-test-cases.xml

@@ -512,4 +512,8 @@
     <dql-test-case sql-case-id="select_for_update">
         <assertion parameters="10:int" expected-data-file="select_for_update.xml" />
     </dql-test-case>
+
+    <dql-test-case sql-case-id="select_with_case_expression">
+        <assertion expected-data-file="select_with_case_expression.xml" />
+    </dql-test-case>
 </integrate-test-cases>

sharding-sql-test/src/main/resources/sql/supported/dml/select-expression.xml

@@ -20,4 +20,6 @@
     <sql-case id="select_with_expression" value="SELECT o.order_id + 1 * 2 as exp FROM t_order AS o ORDER BY o.order_id" />
     <sql-case id="select_with_date_function" value="SELECT DATE(i.creation_date) AS creation_date FROM `t_order_item` AS i ORDER BY DATE(i.creation_date) DESC" db-types="MySQL" />
     <sql-case id="select_with_regexp" value="SELECT * FROM t_order_item t WHERE t.status REGEXP ? AND t.item_id IN (?, ?)" db-types="MySQL" />
+    <sql-case id="select_with_case_expression" value="select t.*,o.item_id as itemid,(case when t.status = 'init' then '已启用' when t.status = 'failed' then '已停用' end) as stateName
+    from t_order t left join t_order_item as o on o.order_id =t.order_id where t.order_id=1000 limit 1" db-types="MySQL,H2" />
 </sql-cases>

shardingsphere-sql-parser/shardingsphere-sql-parser-dialect/shardingsphere-sql-parser-mysql/src/main/java/org/apache/shardingsphere/sql/parser/mysql/visitor/MySQLVisitor.java

@@ -582,7 +582,7 @@ public abstract class MySQLVisitor extends MySQLStatementBaseVisitor<ASTNode> {
     
     @Override
     public final ASTNode visitCaseExpression(final CaseExpressionContext ctx) {
-        return visit(ctx.simpleExpr());
+        return new OtherLiteralValue(ctx.getText());
     }
     
     @Override

shardingsphere-sql-parser/shardingsphere-sql-parser-test/src/test/resources/sql/dml/select-expression.xml

@@ -73,4 +73,35 @@
             </and-predicate>
         </where>
     </select>
+    <select sql-case-id="select_with_case_expression" >
+        <projections start-index="7" stop-index="123">
+            <shorthand-projection start-index="7" stop-index="9">
+                <owner start-index="7" stop-index="7" name="t"/>
+            </shorthand-projection>
+            <column-projection start-index="11" stop-index="19" name="item_id" alias="itemid">
+                <owner start-index="11" stop-index="11" name="o"/>
+            </column-projection>
+            <expression-projection start-index="32" stop-index="109" alias="stateName" />
+        </projections>
+        <tables>
+            <simple-table start-index="134" stop-index="140" name="t_order" alias="t"/>
+            <simple-table start-index="154" stop-index="165" name="t_order_item" alias="o"/>
+        </tables>
+        <where start-index="198" stop-index="218">
+            <and-predicate>
+                <predicate start-index="204" stop-index="218" >
+                    <operator type="="/>
+                    <column-left-value name="order_id" start-index="204" stop-index="213" >
+                        <owner name="t" start-index="204" stop-index="204" />
+                    </column-left-value>
+                    <compare-right-value operator="=">
+                        <literal-expression value="1000" start-index="215" stop-index="218"/>
+                    </compare-right-value>
+                </predicate>
+            </and-predicate>
+        </where>
+        <limit start-index="220" stop-index="226">
+            <row-count value="1" start-index="226" stop-index="226" />
+        </limit>
+    </select>
 </sql-parser-test-cases>