fix: only support join on table of same database

src/client/src/tscSQLParser.c

@@ -10495,6 +10495,7 @@ int32_t validateSqlNode(SSqlObj* pSql, SSqlNode* pSqlNode, SQueryInfo* pQueryInf
   const char* msg8 = "condition missing for join query";
   const char* msg9 = "not support 3 level select";
   const char* msg10 = "limit user forbid query normal or child table, you can query from stable.";
+  const char* msg11 = "only support join on tables of the same database";
 
   int32_t  code = TSDB_CODE_SUCCESS;
   SSqlCmd* pCmd = &pSql->cmd;
@@ -10689,6 +10690,17 @@ int32_t validateSqlNode(SSqlObj* pSql, SSqlNode* pSqlNode, SQueryInfo* pQueryInf
 
     int32_t joinQuery = (pSqlNode->from != NULL && taosArrayGetSize(pSqlNode->from->list) > 1);
 
+    if (joinQuery) {
+      // the code must be done after all table meta is loaded.
+      for (int32_t i = 0; i < (int32_t)numOfTables - 1; ++i) {
+        STableMetaInfo *tmi1 = pQueryInfo->pTableMetaInfo[i];
+        STableMetaInfo *tmi2 = pQueryInfo->pTableMetaInfo[i + 1];
+        if (tmi1 != NULL && tmi2 != NULL && strcmp(tmi1->name.dbname, tmi2->name.dbname) != 0) {
+          return invalidOperationMsg(tscGetErrorMsgPayload(pCmd), msg11);
+        }
+      }
+    }
+
     // parse the group by clause in the first place
     if (validateGroupbyNode(pQueryInfo, pSqlNode->pGroupby, pCmd) != TSDB_CODE_SUCCESS) {
       return TSDB_CODE_TSC_INVALID_OPERATION;

tests/develop-test/2-query/ts_2523.py

+###################################################################
+#           Copyright (c) 2021 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+import sys
+from util.log import *
+from util.cases import *
+from util.sql import *
+
+
+class TDTestCase:
+    def caseDescription(self):
+        '''
+        case1<shenglian zhou>: [TS-2523]join not supported on tables of different databases
+        '''
+        return
+
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor(), logSql)
+        self._conn = conn
+
+    def run(self):
+        print("running {}".format(__file__))
+        tdSql.execute("drop database if exists d1")
+        tdSql.execute("create database if not exists d1")
+        tdSql.execute('use d1')
+
+        tdSql.execute('create stable st(ts timestamp , value int ) tags (ind int)')
+        tdSql.execute('insert into tb1 using st tags(1) values(now ,1)')
+        tdSql.execute('insert into tb1 using st tags(1) values(now+1s ,2)')
+        tdSql.execute('insert into tb1 using st tags(1) values(now+2s ,3)')
+        tdSql.execute("drop database if exists d2")
+        tdSql.execute("create database if not exists d2")
+        tdSql.execute('use d2')
+
+        tdSql.execute('create stable st(ts timestamp , value int ) tags (ind int)')
+        tdSql.execute('insert into tb1 using st tags(1) values(now ,1)')
+        tdSql.execute('insert into tb1 using st tags(1) values(now+1s ,2)')
+        tdSql.execute('insert into tb1 using st tags(1) values(now+2s ,3)')
+
+        tdSql.error('select t1.value, t2.value from d1.st t1, d2.st t2 where t1.ts=t2.ts and t1.ind = t2.ind');
+
+        tdSql.execute('drop database d1')
+        tdSql.execute('drop database d2')
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())
+~

tests/parallel_test/cases.task

@@ -642,6 +642,7 @@
 6,,pytest,python3 test.py -f functions/function_elapsed.py
 6,,pytest,python3 test.py -f alter/alterColMultiTimes.py
 6,,develop-test,python3 ./test.py -f 2-query/ts_2016.py
+6,,develop-test,python3 ./test.py -f 2-query/ts_2523.py
 6,,develop-test,python3 ./test.py -f 2-query/escape.py
 6,,develop-test,python3 ./test.py -f 2-query/TD-14763.py
 5,,system-test,python3 ./test.py -f 4-taosAdapter/taosAdapter_insert.py