td-1245: update sql grammar to support offset

src/client/inc/tsclient.h

@@ -228,10 +228,11 @@ typedef struct SQueryInfo {
   // TODO refactor
   char             intervalTimeUnit;
   char             slidingTimeUnit;
+  char             offsetTimeUnit;
   STimeWindow      window;        // query time window
   int64_t          intervalTime;  // aggregation time window range
   int64_t          slidingTime;   // sliding window in mseconds
-  int64_t          intervalOffset;// start offset of each time window
+  int64_t          offsetTime;    // start offset of each time window
   int32_t          tz;            // query client timezone
 
   SSqlGroupbyExpr  groupbyExpr;   // group by tags info

src/client/src/tscSQLParser.c

@@ -81,6 +81,7 @@ static void setColumnOffsetValueInResultset(SQueryInfo* pQueryInfo);
 static int32_t parseGroupbyClause(SQueryInfo* pQueryInfo, tVariantList* pList, SSqlCmd* pCmd);
 
 static int32_t parseIntervalClause(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, SQuerySQL* pQuerySql);
+static int32_t parseOffsetClause(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, SQuerySQL* pQuerySql);
 static int32_t parseSlidingClause(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, SQuerySQL* pQuerySql);
 
 static int32_t addProjectionExprAndResultField(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, tSQLExprItem* pItem);
@@ -613,6 +614,10 @@ int32_t parseIntervalClause(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, SQuerySQL* pQ
 
   // for top/bottom + interval query, we do not add additional timestamp column in the front
   if (isTopBottomQuery(pQueryInfo)) {
+    if (parseOffsetClause(pCmd, pQueryInfo, pQuerySql) != TSDB_CODE_SUCCESS) {
+      return TSDB_CODE_TSC_INVALID_SQL;
+    }
+
     if (parseSlidingClause(pCmd, pQueryInfo, pQuerySql) != TSDB_CODE_SUCCESS) {
       return TSDB_CODE_TSC_INVALID_SQL;
     }
@@ -662,6 +667,10 @@ int32_t parseIntervalClause(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, SQuerySQL* pQ
   SColumnIndex index = {tableIndex, PRIMARYKEY_TIMESTAMP_COL_INDEX};
   tscAddSpecialColumnForSelect(pQueryInfo, 0, TSDB_FUNC_TS, &index, &s, TSDB_COL_NORMAL);
 
+  if (parseOffsetClause(pCmd, pQueryInfo, pQuerySql) != TSDB_CODE_SUCCESS) {
+    return TSDB_CODE_TSC_INVALID_SQL;
+  }
+
   if (parseSlidingClause(pCmd, pQueryInfo, pQuerySql) != TSDB_CODE_SUCCESS) {
     return TSDB_CODE_TSC_INVALID_SQL;
   }
@@ -669,6 +678,39 @@ int32_t parseIntervalClause(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, SQuerySQL* pQ
   return TSDB_CODE_SUCCESS;
 }
 
+int32_t parseOffsetClause(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, SQuerySQL* pQuerySql) {
+  STableMetaInfo* pTableMetaInfo = tscGetMetaInfo(pQueryInfo, 0);
+  STableComInfo tinfo = tscGetTableInfo(pTableMetaInfo->pTableMeta);
+
+  SStrToken* pOffset = &pQuerySql->offset;
+  if (pOffset->n == 0) {
+    pQueryInfo->offsetTimeUnit = pQueryInfo->offsetTimeUnit;
+    pQueryInfo->offsetTime = 0;
+    return TSDB_CODE_SUCCESS;
+  }
+
+  getTimestampInUsFromStr(pOffset->z, pOffset->n, &pQueryInfo->offsetTime);
+  if (tinfo.precision == TSDB_TIME_PRECISION_MILLI) {
+    pQueryInfo->offsetTime /= 1000;
+  }
+
+/*
+  if (pQueryInfo->offsetTime < 0) {
+    return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg0);
+  }
+
+  if (pQueryInfo->slidingTime >= pQueryInfo->intervalTime) {
+    return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg1);
+  }
+
+  if ((pQueryInfo->intervalTime != 0) && (pQueryInfo->intervalTime/pQueryInfo->slidingTime > INTERVAL_SLIDING_FACTOR)) {
+    return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg2);
+  }
+  */
+
+  return TSDB_CODE_SUCCESS;
+}
+
 int32_t parseSlidingClause(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, SQuerySQL* pQuerySql) {
   const char* msg0 = "sliding value too small";
   const char* msg1 = "sliding value no larger than the interval value";

src/inc/taosmsg.h

@@ -461,10 +461,11 @@ typedef struct {
   int16_t     orderColId;
   int16_t     numOfCols;        // the number of columns will be load from vnode
   int64_t     intervalTime;     // time interval for aggregation, in million second
-  int64_t     intervalOffset;   // start offset for interval query
   int64_t     slidingTime;      // value for sliding window
+  int64_t     offsetTime;       // start offset for interval query
   char        intervalTimeUnit;
   char        slidingTimeUnit;  // time interval type, for revisement of interval(1d)
+  char        offsetTimeUnit;
   uint16_t    tagCondLen;       // tag length in current query
   int16_t     numOfGroupCols;   // num of group by columns
   int16_t     orderByIdx;

src/query/inc/qSqlparser.h

@@ -65,6 +65,11 @@ typedef struct tVariantList {
   tVariantListItem *a;      /* One entry for each expression */
 } tVariantList;
 
+typedef struct SIntervalVal {
+  SStrToken interval;
+  SStrToken offset;
+} SIntervalVal;
+
 typedef struct SQuerySQL {
   struct tSQLExprList *pSelection;   // select clause
   tVariantList *       from;         // from clause
@@ -72,6 +77,7 @@ typedef struct SQuerySQL {
   tVariantList *       pGroupby;     // groupby clause, only for tags[optional]
   tVariantList *       pSortOrder;   // orderby [optional]
   SStrToken            interval;     // interval [optional]
+  SStrToken            offset;       // offset window [optional]
   SStrToken            sliding;      // sliding window [optional]
   SLimitVal            limit;        // limit offset [optional]
   SLimitVal            slimit;       // group limit offset [optional]
@@ -259,7 +265,7 @@ tSQLExprList *tSQLExprListAppend(tSQLExprList *pList, tSQLExpr *pNode, SStrToken
 void tSQLExprListDestroy(tSQLExprList *pList);
 
 SQuerySQL *tSetQuerySQLElems(SStrToken *pSelectToken, tSQLExprList *pSelection, tVariantList *pFrom, tSQLExpr *pWhere,
-                             tVariantList *pGroupby, tVariantList *pSortOrder, SStrToken *pInterval,
+                             tVariantList *pGroupby, tVariantList *pSortOrder, SIntervalVal *pInterval,
                              SStrToken *pSliding, tVariantList *pFill, SLimitVal *pLimit, SLimitVal *pGLimit);
 
 SCreateTableSQL *tSetCreateSQLElems(tFieldList *pCols, tFieldList *pTags, SStrToken *pMetricName,

src/query/inc/sql.y

@@ -458,9 +458,10 @@ tablelist(A) ::= tablelist(Y) COMMA ids(X) cpxName(Z) ids(F). {
 %type tmvar {SStrToken}
 tmvar(A) ::= VARIABLE(X).   {A = X;}
 
-%type interval_opt {SStrToken}
-interval_opt(N) ::= INTERVAL LP tmvar(E) RP.    {N = E;     }
-interval_opt(N) ::= .                           {N.n = 0; N.z = NULL; N.type = 0;   }
+%type interval_opt {SIntervalVal}
+interval_opt(N) ::= INTERVAL LP tmvar(E) RP.    {N.interval = E; N.offset.n = 0; N.offset.z = NULL; N.offset.type = 0;}
+interval_opt(N) ::= INTERVAL LP tmvar(E) COMMA tmvar(O) RP.    {N.interval = E; N.offset = O;}
+interval_opt(N) ::= .                           {memset(&N, 0, sizeof(N));}
 
 %type fill_opt {tVariantList*}
 %destructor fill_opt {tVariantListDestroy($$);}

src/query/src/qParserImpl.c

@@ -535,7 +535,7 @@ void tSQLSetColumnType(TAOS_FIELD *pField, SStrToken *type) {
  * extract the select info out of sql string
  */
 SQuerySQL *tSetQuerySQLElems(SStrToken *pSelectToken, tSQLExprList *pSelection, tVariantList *pFrom, tSQLExpr *pWhere,
-                             tVariantList *pGroupby, tVariantList *pSortOrder, SStrToken *pInterval,
+                             tVariantList *pGroupby, tVariantList *pSortOrder, SIntervalVal *pInterval,
                              SStrToken *pSliding, tVariantList *pFill, SLimitVal *pLimit, SLimitVal *pGLimit) {
   assert(pSelection != NULL);
 
@@ -558,7 +558,8 @@ SQuerySQL *tSetQuerySQLElems(SStrToken *pSelectToken, tSQLExprList *pSelection,
   }
 
   if (pInterval != NULL) {
-    pQuery->interval = *pInterval;
+    pQuery->interval = pInterval->interval;
+    pQuery->offset = pInterval->offset;
   }
 
   if (pSliding != NULL) {