diff --git a/source/libs/parser/src/parAstParser.c b/source/libs/parser/src/parAstParser.c
index 64aa017a68f7cfb04d0b69c5b526ebeea179b251..95db6b93c901fabd53368d58d2f1b6f0936952c9 100644
--- a/source/libs/parser/src/parAstParser.c
+++ b/source/libs/parser/src/parAstParser.c
@@ -455,8 +455,13 @@ static int32_t collectMetaKeyFromShowLicence(SCollectMetaKeyCxt* pCxt, SShowStmt
 }
 
 static int32_t collectMetaKeyFromShowVgroups(SCollectMetaKeyCxt* pCxt, SShowStmt* pStmt) {
-  return reserveTableMetaInCache(pCxt->pParseCxt->acctId, TSDB_INFORMATION_SCHEMA_DB, TSDB_INS_TABLE_VGROUPS,
-                                 pCxt->pMetaCache);
+  int32_t code = reserveTableMetaInCache(pCxt->pParseCxt->acctId, TSDB_INFORMATION_SCHEMA_DB, TSDB_INS_TABLE_VGROUPS,
+                                         pCxt->pMetaCache);
+  if (TSDB_CODE_SUCCESS == code) {
+    // just to verify whether the database exists
+    code = reserveDbCfgInCache(pCxt->pParseCxt->acctId, ((SValueNode*)pStmt->pDbName)->literal, pCxt->pMetaCache);
+  }
+  return code;
 }
 
 static int32_t collectMetaKeyFromShowTopics(SCollectMetaKeyCxt* pCxt, SShowStmt* pStmt) {
diff --git a/source/libs/parser/src/parTranslater.c b/source/libs/parser/src/parTranslater.c
index 8dd4577a96fe155ffc8769d82839fc84003d4381..d942af9673aa201c2a8dd4fc92fa1f994b8c0ba8 100644
--- a/source/libs/parser/src/parTranslater.c
+++ b/source/libs/parser/src/parTranslater.c
@@ -6212,6 +6212,20 @@ static int32_t rewriteShow(STranslateContext* pCxt, SQuery* pQuery) {
   return code;
 }
 
+static int32_t checkShowVgroups(STranslateContext* pCxt, SShowStmt* pShow) {
+  // just to verify whether the database exists
+  SDbCfgInfo dbCfg = {0};
+  return getDBCfg(pCxt, ((SValueNode*)pShow->pDbName)->literal, &dbCfg);
+}
+
+static int32_t rewriteShowVgroups(STranslateContext* pCxt, SQuery* pQuery) {
+  int32_t code = checkShowVgroups(pCxt, (SShowStmt*)pQuery->pRoot);
+  if (TSDB_CODE_SUCCESS == code) {
+    code = rewriteShow(pCxt, pQuery);
+  }
+  return code;
+}
+
 static SNode* createTagsFunction() {
   SFunctionNode* pFunc = (SFunctionNode*)nodesMakeNode(QUERY_NODE_FUNCTION);
   if (NULL == pFunc) {
@@ -7358,7 +7372,6 @@ static int32_t rewriteQuery(STranslateContext* pCxt, SQuery* pQuery) {
     case QUERY_NODE_SHOW_STABLES_STMT:
     case QUERY_NODE_SHOW_USERS_STMT:
     case QUERY_NODE_SHOW_DNODES_STMT:
-    case QUERY_NODE_SHOW_VGROUPS_STMT:
     case QUERY_NODE_SHOW_MNODES_STMT:
     case QUERY_NODE_SHOW_MODULES_STMT:
     case QUERY_NODE_SHOW_QNODES_STMT:
@@ -7378,6 +7391,9 @@ static int32_t rewriteQuery(STranslateContext* pCxt, SQuery* pQuery) {
     case QUERY_NODE_SHOW_TAGS_STMT:
       code = rewriteShow(pCxt, pQuery);
       break;
+    case QUERY_NODE_SHOW_VGROUPS_STMT:
+      code = rewriteShowVgroups(pCxt, pQuery);
+      break;
     case QUERY_NODE_SHOW_TABLE_TAGS_STMT:
       code = rewriteShowStableTags(pCxt, pQuery);
       break;
diff --git a/tools/shell/src/shellEngine.c b/tools/shell/src/shellEngine.c
index 37d00c0a7ce9d5a2d91ae7a2f9747097361e2c1f..d5c765e8c5b0fcf38080a58e605a52e29a859bb2 100644
--- a/tools/shell/src/shellEngine.c
+++ b/tools/shell/src/shellEngine.c
@@ -282,9 +282,14 @@ char *shellFormatTimestamp(char *buf, int64_t val, int32_t precision) {
 
 void shellDumpFieldToFile(TdFilePtr pFile, const char *val, TAOS_FIELD *field, int32_t length, int32_t precision) {
   if (val == NULL) {
+    taosFprintfFile(pFile, "NULL");
     return;
   }
 
+  char quotationStr[2];
+  quotationStr[0] = '\"';
+  quotationStr[1] = 0;
+
   int  n;
   char buf[TSDB_MAX_BYTES_PER_ROW];
   switch (field->type) {
@@ -330,33 +335,23 @@ void shellDumpFieldToFile(TdFilePtr pFile, const char *val, TAOS_FIELD *field, i
     case TSDB_DATA_TYPE_NCHAR:
     case TSDB_DATA_TYPE_JSON:
       {
-        char quotationStr[2];
         int32_t bufIndex = 0;
-        quotationStr[0] = 0;
-        quotationStr[1] = 0;
         for (int32_t i = 0; i < length; i++) {
           buf[bufIndex] = val[i];
           bufIndex++;
           if (val[i] == '\"') {
             buf[bufIndex] = val[i];
             bufIndex++;
-            quotationStr[0] = '\"';
-          }
-          if (val[i] == ',') {
-            quotationStr[0] = '\"';
           }
         }
         buf[bufIndex] = 0;
-        if (length == 0) {
-          quotationStr[0] = '\"';
-        }
         
         taosFprintfFile(pFile, "%s%s%s", quotationStr, buf, quotationStr);
       }
       break;
     case TSDB_DATA_TYPE_TIMESTAMP:
       shellFormatTimestamp(buf, *(int64_t *)val, precision);
-      taosFprintfFile(pFile, "%s", buf);
+      taosFprintfFile(pFile, "%s%s%s", quotationStr, buf, quotationStr);
       break;
     default:
       break;
diff --git a/utils/test/c/tmqSim.c b/utils/test/c/tmqSim.c
index 7452a67fedea038bbcdc2cf7abf417f6b9329cb7..f77a910f3571fd94b8c47d03b27f17e05223e599 100644
--- a/utils/test/c/tmqSim.c
+++ b/utils/test/c/tmqSim.c
@@ -497,9 +497,14 @@ static char* shellFormatTimestamp(char* buf, int64_t val, int32_t precision) {
 static void shellDumpFieldToFile(TdFilePtr pFile, const char* val, TAOS_FIELD* field, int32_t length,
                                  int32_t precision) {
   if (val == NULL) {
+    taosFprintfFile(pFile, "NULL");
     return;
   }
 
+  char quotationStr[2];
+  quotationStr[0] = '\"';
+  quotationStr[1] = 0;
+
   int  n;
   char buf[TSDB_MAX_BYTES_PER_ROW];
   switch (field->type) {
@@ -545,33 +550,23 @@ static void shellDumpFieldToFile(TdFilePtr pFile, const char* val, TAOS_FIELD* f
     case TSDB_DATA_TYPE_NCHAR:
     case TSDB_DATA_TYPE_JSON:
       {
-        char quotationStr[2];
         int32_t bufIndex = 0;
-        quotationStr[0] = 0;
-        quotationStr[1] = 0;
         for (int32_t i = 0; i < length; i++) {
           buf[bufIndex] = val[i];
           bufIndex++;
           if (val[i] == '\"') {
             buf[bufIndex] = val[i];
             bufIndex++;
-            quotationStr[0] = '\"';
-          }
-          if (val[i] == ',') {
-            quotationStr[0] = '\"';
           }
         }
         buf[bufIndex] = 0;
-        if (length == 0) {
-          quotationStr[0] = '\"';
-        }
         
         taosFprintfFile(pFile, "%s%s%s", quotationStr, buf, quotationStr);
       }
       break;
     case TSDB_DATA_TYPE_TIMESTAMP:
       shellFormatTimestamp(buf, *(int64_t*)val, precision);
-      taosFprintfFile(pFile, "%s", buf);
+      taosFprintfFile(pFile, "%s%s%s", quotationStr, buf, quotationStr);
       break;
     default:
       break;