Merge pull request #20206 from taosdata/fix/main_wxy

fix: a plan error of set operator subquery

source/libs/parser/src/parCalcConst.c

@@ -320,6 +320,79 @@ static int32_t calcConstInsert(SCalcConstContext* pCxt, SInsertStmt* pInsert) {
   return code;
 }
 
+static SNodeList* getChildProjection(SNode* pStmt) {
+  switch (nodeType(pStmt)) {
+    case QUERY_NODE_SELECT_STMT:
+      return ((SSelectStmt*)pStmt)->pProjectionList;
+    case QUERY_NODE_SET_OPERATOR:
+      return ((SSetOperator*)pStmt)->pProjectionList;
+    default:
+      break;
+  }
+  return NULL;
+}
+
+static void eraseSetOpChildProjection(SSetOperator* pSetOp, int32_t index) {
+  SNodeList* pLeftProjs = getChildProjection(pSetOp->pLeft);
+  nodesListErase(pLeftProjs, nodesListGetCell(pLeftProjs, index));
+  SNodeList* pRightProjs = getChildProjection(pSetOp->pRight);
+  nodesListErase(pRightProjs, nodesListGetCell(pRightProjs, index));
+}
+
+typedef struct SNotRefByOrderByCxt {
+  SColumnNode* pCol;
+  bool         hasThisCol;
+} SNotRefByOrderByCxt;
+
+static EDealRes notRefByOrderByImpl(SNode* pNode, void* pContext) {
+  if (QUERY_NODE_COLUMN == nodeType(pNode)) {
+    SNotRefByOrderByCxt* pCxt = (SNotRefByOrderByCxt*)pContext;
+    if (nodesEqualNode((SNode*)pCxt->pCol, pNode)) {
+      pCxt->hasThisCol = true;
+      return DEAL_RES_END;
+    }
+  }
+  return DEAL_RES_CONTINUE;
+}
+
+static bool notRefByOrderBy(SColumnNode* pCol, SNodeList* pOrderByList) {
+  SNotRefByOrderByCxt cxt = {.pCol = pCol, .hasThisCol = false};
+  nodesWalkExprs(pOrderByList, notRefByOrderByImpl, &cxt);
+  return !cxt.hasThisCol;
+}
+
+static int32_t calcConstSetOpProjections(SCalcConstContext* pCxt, SSetOperator* pSetOp, bool subquery) {
+  int32_t index = 0;
+  SNode*  pProj = NULL;
+  WHERE_EACH(pProj, pSetOp->pProjectionList) {
+    if (subquery && notRefByOrderBy((SColumnNode*)pProj, pSetOp->pOrderByList) && isUselessCol((SExprNode*)pProj)) {
+      ERASE_NODE(pSetOp->pProjectionList);
+      eraseSetOpChildProjection(pSetOp, index);
+      continue;
+    }
+    ++index;
+    WHERE_NEXT;
+  }
+  if (0 == LIST_LENGTH(pSetOp->pProjectionList)) {
+    return nodesListStrictAppend(pSetOp->pProjectionList, createConstantValue());
+  }
+  return TSDB_CODE_SUCCESS;
+}
+
+static int32_t calcConstSetOperator(SCalcConstContext* pCxt, SSetOperator* pSetOp, bool subquery) {
+  int32_t code = calcConstSetOpProjections(pCxt, pSetOp, subquery);
+  if (TSDB_CODE_SUCCESS == code) {
+    code = calcConstQuery(pCxt, pSetOp->pLeft, false);
+  }
+  if (TSDB_CODE_SUCCESS == code) {
+    code = calcConstQuery(pCxt, pSetOp->pRight, false);
+  }
+  if (TSDB_CODE_SUCCESS == code) {
+    code = calcConstList(pSetOp->pOrderByList);
+  }
+  return code;
+}
+
 static int32_t calcConstQuery(SCalcConstContext* pCxt, SNode* pStmt, bool subquery) {
   int32_t code = TSDB_CODE_SUCCESS;
   switch (nodeType(pStmt)) {
@@ -330,11 +403,7 @@ static int32_t calcConstQuery(SCalcConstContext* pCxt, SNode* pStmt, bool subque
       code = calcConstQuery(pCxt, ((SExplainStmt*)pStmt)->pQuery, subquery);
       break;
     case QUERY_NODE_SET_OPERATOR: {
-      SSetOperator* pSetOp = (SSetOperator*)pStmt;
-      code = calcConstQuery(pCxt, pSetOp->pLeft, false);
-      if (TSDB_CODE_SUCCESS == code) {
-        code = calcConstQuery(pCxt, pSetOp->pRight, false);
-      }
+      code = calcConstSetOperator(pCxt, (SSetOperator*)pStmt, subquery);
       break;
     }
     case QUERY_NODE_DELETE_STMT: