diff --git a/.gitignore b/.gitignore
index 0eba25231f2a4961dd31f847458850a455788a58..091e1d7361495df8da21c79f77e90cc20e595596 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,6 +5,7 @@ build/
 cmake-build-debug/
 cmake-build-release/
 cscope.out
+cscope.files
 .DS_Store
 debug/
 release/
diff --git a/src/client/src/tscLocal.c b/src/client/src/tscLocal.c
index 81d658d964dc2a404e04f363751e0a17ebe6e46f..b3da64f011a86ec31baa60bcc5e5c43ca9aaec9a 100644
--- a/src/client/src/tscLocal.c
+++ b/src/client/src/tscLocal.c
@@ -533,8 +533,8 @@ static int32_t tscGetDBInfo(SCreateBuilder *builder, char *result) {
     memset(buf, 0, sizeof(buf));
     int32_t* lengths = taos_fetch_lengths(pSql);
     int32_t ret = tscGetNthFieldResult(row, fields, lengths, 0, buf);
-    if (0 == ret && STR_NOCASE_EQUAL(buf, strlen(buf), builder->buf, strlen(builder->buf))) {
-      snprintf(result + strlen(result), TSDB_MAX_BINARY_LEN - strlen(result), "CREATE DATABASE %s", buf);
+    if (0 == ret && 0 == strcmp(buf, builder->buf)) {
+      snprintf(result + strlen(result), TSDB_MAX_BINARY_LEN - strlen(result), "CREATE DATABASE `%s`", buf);
       for (int i = 1; i < num_fields; i++) {
         for (int j = 0; showColumns[j][0] != NULL; j++) {
           if (STR_NOCASE_EQUAL(fields[i].name, strlen(fields[i].name), showColumns[j][0], strlen(showColumns[j][0]))) {
diff --git a/src/client/src/tscSQLParser.c b/src/client/src/tscSQLParser.c
index dc128a8aad240f95847447d012c2f0b9d76ea927..715262438dd71e09500cfd1f35327fd055978d82 100644
--- a/src/client/src/tscSQLParser.c
+++ b/src/client/src/tscSQLParser.c
@@ -606,8 +606,7 @@ int32_t tscValidateSqlInfo(SSqlObj* pSql, struct SSqlInfo* pInfo) {
     case TSDB_SQL_DROP_TABLE:
     case TSDB_SQL_DROP_USER:
     case TSDB_SQL_DROP_ACCT:
-    case TSDB_SQL_DROP_DNODE:
-    case TSDB_SQL_DROP_DB: {
+    case TSDB_SQL_DROP_DNODE: {
       const char* msg2 = "invalid name";
       const char* msg3 = "param name too long";
 
@@ -626,14 +625,7 @@ int32_t tscValidateSqlInfo(SSqlObj* pSql, struct SSqlInfo* pInfo) {
         }
       }
 
-      if (pInfo->type == TSDB_SQL_DROP_DB) {
-        assert(taosArrayGetSize(pInfo->pMiscInfo->a) == 1);
-        code = tNameSetDbName(&pTableMetaInfo->name, getAccountId(pSql), pzName);
-        if (code != TSDB_CODE_SUCCESS) {
-          return invalidOperationMsg(tscGetErrorMsgPayload(pCmd), msg2);
-        }
-
-      } else if (pInfo->type == TSDB_SQL_DROP_TABLE) {
+      if (pInfo->type == TSDB_SQL_DROP_TABLE) {
         assert(taosArrayGetSize(pInfo->pMiscInfo->a) == 1);
 
         code = tscSetTableFullName(&pTableMetaInfo->name, &sTblToken, pSql, dbIncluded);
@@ -656,11 +648,12 @@ int32_t tscValidateSqlInfo(SSqlObj* pSql, struct SSqlInfo* pInfo) {
       break;
     }
 
+    case TSDB_SQL_DROP_DB:
     case TSDB_SQL_USE_DB: {
       const char* msg = "invalid db name";
       SStrToken* pToken = taosArrayGet(pInfo->pMiscInfo->a, 0);
 
-      if (tscValidateName(pToken, false, NULL) != TSDB_CODE_SUCCESS) {
+      if (tscValidateName(pToken, true, NULL) != TSDB_CODE_SUCCESS) {
         return invalidOperationMsg(tscGetErrorMsgPayload(pCmd), msg);
       }
 
@@ -707,7 +700,7 @@ int32_t tscValidateSqlInfo(SSqlObj* pSql, struct SSqlInfo* pInfo) {
       char buf[TSDB_DB_NAME_LEN] = {0};
       SStrToken token = taosTokenDup(&pCreateDB->dbname, buf, tListLen(buf));
 
-      if (tscValidateName(&token, false, NULL) != TSDB_CODE_SUCCESS) {
+      if (tscValidateName(&token, true, NULL) != TSDB_CODE_SUCCESS) {
         return invalidOperationMsg(tscGetErrorMsgPayload(pCmd), msg1);
       }
 
@@ -820,7 +813,7 @@ int32_t tscValidateSqlInfo(SSqlObj* pSql, struct SSqlInfo* pInfo) {
 
       SStrToken* pToken = taosArrayGet(pInfo->pMiscInfo->a, 0);
 
-      if (tscValidateName(pToken, false, NULL) != TSDB_CODE_SUCCESS) {
+      if (tscValidateName(pToken, true, NULL) != TSDB_CODE_SUCCESS) {
         return invalidOperationMsg(tscGetErrorMsgPayload(pCmd), msg1);
       }
 
@@ -1747,7 +1740,7 @@ int32_t validateOneTag(SSqlCmd* pCmd, TAOS_FIELD* pTagField) {
   SSchema* pSchema = tscGetTableSchema(pTableMeta);
 
   for (int32_t i = 0; i < numOfTags + numOfCols; ++i) {
-    if (strncasecmp(pTagField->name, pSchema[i].name, sizeof(pTagField->name) - 1) == 0) {
+    if (strncmp(pTagField->name, pSchema[i].name, sizeof(pTagField->name) - 1) == 0) {
       //return tscErrorMsgWithCode(TSDB_CODE_TSC_DUP_COL_NAMES, tscGetErrorMsgPayload(pCmd), pTagField->name, NULL);
       return invalidOperationMsg(tscGetErrorMsgPayload(pCmd), "duplicated column names");
     }
@@ -2214,10 +2207,6 @@ int32_t validateSelectNodeList(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, SArray* pS
        hasDistinct = (pItem->distinct == true);
        distIdx     =  hasDistinct ? i : -1;
     }
-    if(pItem->aliasName != NULL && validateColumnName(pItem->aliasName) != TSDB_CODE_SUCCESS){
-      return invalidOperationMsg(tscGetErrorMsgPayload(pCmd), msg11);
-    }
-
     if(pItem->aliasName != NULL && strcasecmp(pItem->aliasName, DEFAULT_PRIMARY_TIMESTAMP_COL_NAME) == 0){
       return invalidOperationMsg(tscGetErrorMsgPayload(pCmd), msg11);
     }
@@ -3600,7 +3589,7 @@ int32_t setShowInfo(SSqlObj* pSql, struct SSqlInfo* pInfo) {
       if (pDbPrefixToken->n <= 0) {
         return invalidOperationMsg(tscGetErrorMsgPayload(pCmd), msg5);
       }
-      if (tscValidateName(pDbPrefixToken, false, NULL) != TSDB_CODE_SUCCESS) {
+      if (tscValidateName(pDbPrefixToken, true, NULL) != TSDB_CODE_SUCCESS) {
         return invalidOperationMsg(tscGetErrorMsgPayload(pCmd), msg1);
       }
 
@@ -6043,13 +6032,13 @@ static int32_t getQueryTimeRange(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, tSqlExpr
   if (*pExpr == NULL) {
     return ret;
   }
-  
+
   //multiple tables's query time range mixed together
-  
+
   tExprNode* p = NULL;
   void *filter = NULL;
 
-  SArray* colList = taosArrayInit(10, sizeof(SColIndex));  
+  SArray* colList = taosArrayInit(10, sizeof(SColIndex));
   ret = exprTreeFromSqlExpr(pCmd, &p, *pExpr, pQueryInfo, colList, NULL);
   taosArrayDestroy(&colList);
 
diff --git a/src/client/src/tscUtil.c b/src/client/src/tscUtil.c
index 9ed79a939fc10d8c03aaa977664314e1d79c4147..ec09e791d1346aef747b9aafc23e49b7061f83a9 100644
--- a/src/client/src/tscUtil.c
+++ b/src/client/src/tscUtil.c
@@ -3035,6 +3035,12 @@ int32_t tscValidateName(SStrToken* pToken, bool escapeEnabled, bool *dbIncluded)
       }
     }
 
+    if (escapeEnabled && pToken->type == TK_ID) {
+      if (pToken->z[0] == TS_BACKQUOTE_CHAR) {
+        pToken->n = stringProcess(pToken->z, pToken->n);
+        firstPartQuote = true;
+      }
+    }
     int32_t firstPartLen = pToken->n;
 
     pToken->z = sep + 1;
diff --git a/src/kit/shell/src/shellEngine.c b/src/kit/shell/src/shellEngine.c
index 21f27a9255596f79638274da8cd70484750bb8f9..53e4b32e0cc2235db7af8dfc85d0b02b6482dc20 100644
--- a/src/kit/shell/src/shellEngine.c
+++ b/src/kit/shell/src/shellEngine.c
@@ -301,7 +301,7 @@ void shellRunCommandOnServer(TAOS *con, char command[]) {
 
   int64_t oresult = atomic_load_64(&result);
 
-  if (regex_match(command, "^\\s*use\\s+[a-zA-Z0-9_]+\\s*;\\s*$", REG_EXTENDED | REG_ICASE)) {
+  if (regex_match(command, "^\\s*use\\s+([a-zA-Z0-9_]+|`.+`)\\s*;\\s*$", REG_EXTENDED | REG_ICASE)) {
     fprintf(stdout, "Database changed.\n\n");
     fflush(stdout);
 
diff --git a/src/mnode/src/mnodeTable.c b/src/mnode/src/mnodeTable.c
index 116c1f41d7c240e266db7c0d93168c8e3ddc6d15..cbf37f976eb882e88bcd049682e06157bac606ff 100644
--- a/src/mnode/src/mnodeTable.c
+++ b/src/mnode/src/mnodeTable.c
@@ -1225,7 +1225,7 @@ static int32_t mnodeProcessDropSuperTableMsg(SMnodeMsg *pMsg) {
 static int32_t mnodeFindSuperTableTagIndex(SSTableObj *pStable, const char *tagName) {
   SSchema *schema = (SSchema *) pStable->schema;
   for (int32_t tag = 0; tag < pStable->numOfTags; tag++) {
-    if (strcasecmp(schema[pStable->numOfColumns + tag].name, tagName) == 0) {
+    if (strcmp(schema[pStable->numOfColumns + tag].name, tagName) == 0) {
       return tag;
     }
   }
@@ -1378,7 +1378,7 @@ static int32_t mnodeModifySuperTableTagName(SMnodeMsg *pMsg, char *oldTagName, c
 static int32_t mnodeFindSuperTableColumnIndex(SSTableObj *pStable, char *colName) {
   SSchema *schema = (SSchema *) pStable->schema;
   for (int32_t col = 0; col < pStable->numOfColumns; col++) {
-    if (strcasecmp(schema[col].name, colName) == 0) {
+    if (strcmp(schema[col].name, colName) == 0) {
       return col;
     }
   }
diff --git a/src/plugins/monitor/src/monMain.c b/src/plugins/monitor/src/monMain.c
index dac264e4180303a974271b0978449c502c86479d..1ff2f0ef8dd837496078742b7c95ccd4264acd45 100644
--- a/src/plugins/monitor/src/monMain.c
+++ b/src/plugins/monitor/src/monMain.c
@@ -719,13 +719,13 @@ static int32_t monBuildMnodesTotalSql(char *sql) {
 
 static int32_t monGetVgroupsTotalStats(char *dbName, int32_t *totalVgroups,
                                            int32_t *totalVgroupsAlive) {
-  char subsql[TSDB_DB_NAME_LEN + 14];
+  char subsql[TSDB_DB_NAME_LEN + 16];
   memset(subsql, 0, sizeof(subsql));
-  snprintf(subsql, TSDB_DB_NAME_LEN + 13, "show %s.vgroups", dbName);
+  snprintf(subsql, sizeof(subsql) - 1, "show `%s`.vgroups", dbName);
   TAOS_RES *result = taos_query(tsMonitor.conn, subsql);
   int32_t code = taos_errno(result);
   if (code != TSDB_CODE_SUCCESS) {
-    monError("failed to execute cmd: show %s.vgroups, reason:%s", dbName, tstrerror(code));
+    monError("failed to execute cmd: show `%s`.vgroups, reason:%s", dbName, tstrerror(code));
   }
 
   TAOS_ROW    row;
@@ -1110,11 +1110,11 @@ static uint32_t monBuildVgroupsInfoSql(char *sql, char *dbName) {
   int64_t ts = taosGetTimestampUs();
 
   memset(sql, 0, SQL_LENGTH + 1);
-  snprintf(sql, SQL_LENGTH, "show %s.vgroups", dbName);
+  snprintf(sql, SQL_LENGTH, "show `%s`.vgroups", dbName);
   TAOS_RES *result = taos_query(tsMonitor.conn, sql);
   int32_t code = taos_errno(result);
   if (code != TSDB_CODE_SUCCESS) {
-    monError("failed to execute cmd: show %s.vgroups, reason:%s", dbName, tstrerror(code));
+    monError("failed to execute cmd: show `%s`.vgroups, reason:%s", dbName, tstrerror(code));
   }
 
   TAOS_ROW    row;