[TD-2573]<fix>: functions nesting are not allowed

src/client/src/tscSQLParser.c

@@ -2733,6 +2733,11 @@ int32_t addExprAndResultField(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, int32_t col
             }
 
             pTableMetaInfo = tscGetMetaInfo(pQueryInfo, index.tableIndex);
+            SSchema* pSchema = tscGetTableColumnSchema(pTableMetaInfo->pTableMeta, index.columnIndex);
+
+            if (!IS_NUMERIC_TYPE(pSchema->type)) {
+              return invalidOperationMsg(tscGetErrorMsgPayload(pCmd), msg1);
+            }
 
             // functions can not be applied to tags
             if ((index.columnIndex >= tscGetNumOfColumns(pTableMetaInfo->pTableMeta)) || (index.columnIndex < 0)) {
@@ -2740,7 +2745,6 @@ int32_t addExprAndResultField(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, int32_t col
             }
 
             char name[TSDB_COL_NAME_LEN] = {0};
-            SSchema* pSchema = tscGetTableColumnSchema(pTableMetaInfo->pTableMeta, index.columnIndex);
 
             bool multiColOutput = taosArrayGetSize(pItem->pNode->Expr.paramList) > 1;
             setResultColName(name, pItem, cvtFunc.originFuncId, &pParamElem->pNode->columnName, multiColOutput);