diff --git a/source/libs/nodes/src/nodesCodeFuncs.c b/source/libs/nodes/src/nodesCodeFuncs.c
index 5d007db29bcb8bcc07514e87feea5e3557aca302..1c72a90c132a06c7bd1d292327892c6f1290face 100644
--- a/source/libs/nodes/src/nodesCodeFuncs.c
+++ b/source/libs/nodes/src/nodesCodeFuncs.c
@@ -1040,7 +1040,7 @@ static int32_t datumToJson(const void* pObj, SJson* pJson) {
     case TSDB_DATA_TYPE_NCHAR:
     case TSDB_DATA_TYPE_VARCHAR:
     case TSDB_DATA_TYPE_VARBINARY:
-      code = tjsonAddStringToObject(pJson, jkValueDatum, pNode->datum.p);
+      code = tjsonAddStringToObject(pJson, jkValueDatum, varDataVal(pNode->datum.p));
       break;
     case TSDB_DATA_TYPE_JSON:
     case TSDB_DATA_TYPE_DECIMAL:
@@ -1103,9 +1103,16 @@ static int32_t jsonToDatum(const SJson* pJson, void* pObj) {
     case TSDB_DATA_TYPE_BINARY:
     case TSDB_DATA_TYPE_NCHAR:
     case TSDB_DATA_TYPE_VARCHAR:
-    case TSDB_DATA_TYPE_VARBINARY:
-      code = tjsonDupStringValue(pJson, jkValueDatum, &pNode->datum.p);
+    case TSDB_DATA_TYPE_VARBINARY: {
+      pNode->datum.p = calloc(1, pNode->node.resType.bytes);
+      if (NULL == pNode->datum.p) {
+        code = TSDB_CODE_OUT_OF_MEMORY;
+        break;
+      }
+      varDataSetLen(pNode->datum.p, pNode->node.resType.bytes);
+      code = tjsonGetStringValue(pJson, jkValueDatum, varDataVal(pNode->datum.p));
       break;
+    }
     case TSDB_DATA_TYPE_JSON:
     case TSDB_DATA_TYPE_DECIMAL:
     case TSDB_DATA_TYPE_BLOB:
diff --git a/source/libs/parser/inc/parAst.h b/source/libs/parser/inc/parAst.h
index 5470c672357c79fac82a0787b07c3b2fff11249d..7ecfe626cec879d7d0db3babfbb1fa004e74e010 100644
--- a/source/libs/parser/inc/parAst.h
+++ b/source/libs/parser/inc/parAst.h
@@ -80,6 +80,7 @@ SNodeList* addNodeToList(SAstCreateContext* pCxt, SNodeList* pList, SNode* pNode
 SNode* createColumnNode(SAstCreateContext* pCxt, const SToken* pTableAlias, const SToken* pColumnName);
 SNode* createValueNode(SAstCreateContext* pCxt, int32_t dataType, const SToken* pLiteral);
 SNode* createDurationValueNode(SAstCreateContext* pCxt, const SToken* pLiteral);
+SNode* createDefaultDatabaseCondValue(SAstCreateContext* pCxt);
 SNode* setProjectionAlias(SAstCreateContext* pCxt, SNode* pNode, const SToken* pAlias);
 SNode* createLogicConditionNode(SAstCreateContext* pCxt, ELogicConditionType type, SNode* pParam1, SNode* pParam2);
 SNode* createOperatorNode(SAstCreateContext* pCxt, EOperatorType type, SNode* pLeft, SNode* pRight);
diff --git a/source/libs/parser/inc/sql.y b/source/libs/parser/inc/sql.y
index 2074c185332dc4b6e07834625141f69ec1020f69..c49ffd6d90894597c359dd38023f8700adfda596 100644
--- a/source/libs/parser/inc/sql.y
+++ b/source/libs/parser/inc/sql.y
@@ -203,7 +203,7 @@ cmd ::= SHOW FUNCTIONS.
 cmd ::= SHOW INDEXES FROM table_name_cond(A) from_db_opt(B).                      { pCxt->pRootNode = createShowStmt(pCxt, QUERY_NODE_SHOW_INDEXES_STMT, A, B); }
 cmd ::= SHOW STREAMS.                                                             { pCxt->pRootNode = createShowStmt(pCxt, QUERY_NODE_SHOW_STREAMS_STMT, NULL, NULL); }
 
-db_name_cond_opt(A) ::= .                                                         { A = NULL; }
+db_name_cond_opt(A) ::= .                                                         { A = createDefaultDatabaseCondValue(pCxt); }
 db_name_cond_opt(A) ::= db_name(B) NK_DOT.                                        { A = createValueNode(pCxt, TSDB_DATA_TYPE_BINARY, &B); }
 
 like_pattern_opt(A) ::= .                                                         { A = NULL; }
@@ -211,7 +211,7 @@ like_pattern_opt(A) ::= LIKE NK_STRING(B).
 
 table_name_cond(A) ::= table_name(B).                                             { A = createValueNode(pCxt, TSDB_DATA_TYPE_BINARY, &B); }
 
-from_db_opt(A) ::= .                                                              { A = NULL; }
+from_db_opt(A) ::= .                                                              { A = createDefaultDatabaseCondValue(pCxt); }
 from_db_opt(A) ::= FROM db_name(B).                                               { A = createValueNode(pCxt, TSDB_DATA_TYPE_BINARY, &B); }
 
 /************************************************ select **************************************************************/
diff --git a/source/libs/parser/src/parAstCreater.c b/source/libs/parser/src/parAstCreater.c
index f8086e8a6390ed7bd23fced817e794f68b0cf65f..4ba989ca3e9e15a51a1189da697277b0568d76a3 100644
--- a/source/libs/parser/src/parAstCreater.c
+++ b/source/libs/parser/src/parAstCreater.c
@@ -489,9 +489,12 @@ SNode* createValueNode(SAstCreateContext* pCxt, int32_t dataType, const SToken*
   SValueNode* val = (SValueNode*)nodesMakeNode(QUERY_NODE_VALUE);
   CHECK_OUT_OF_MEM(val);
   val->literal = strndup(pLiteral->z, pLiteral->n);
+  if (IS_VAR_DATA_TYPE(dataType) || TSDB_DATA_TYPE_TIMESTAMP == dataType) {
+    trimString(pLiteral->z, pLiteral->n, val->literal, pLiteral->n);
+  }
   CHECK_OUT_OF_MEM(val->literal);
   val->node.resType.type = dataType;
-  val->node.resType.bytes = tDataTypes[dataType].bytes;
+  val->node.resType.bytes = IS_VAR_DATA_TYPE(dataType) ? strlen(val->literal) : tDataTypes[dataType].bytes;
   if (TSDB_DATA_TYPE_TIMESTAMP == dataType) {
     val->node.resType.precision = TSDB_TIME_PRECISION_MILLI;
   }
@@ -513,6 +516,19 @@ SNode* createDurationValueNode(SAstCreateContext* pCxt, const SToken* pLiteral)
   return (SNode*)val;
 }
 
+SNode* createDefaultDatabaseCondValue(SAstCreateContext* pCxt) {
+  SValueNode* val = (SValueNode*)nodesMakeNode(QUERY_NODE_VALUE);
+  CHECK_OUT_OF_MEM(val);
+  val->literal = strdup(pCxt->pQueryCxt->db);
+  CHECK_OUT_OF_MEM(val->literal);
+  val->isDuration = false;
+  val->translate = false;
+  val->node.resType.type = TSDB_DATA_TYPE_BINARY;
+  val->node.resType.bytes = strlen(val->literal);
+  val->node.resType.precision = TSDB_TIME_PRECISION_MILLI;
+  return (SNode*)val;
+}
+
 SNode* createLogicConditionNode(SAstCreateContext* pCxt, ELogicConditionType type, SNode* pParam1, SNode* pParam2) {
   SLogicConditionNode* cond = (SLogicConditionNode*)nodesMakeNode(QUERY_NODE_LOGIC_CONDITION);
   CHECK_OUT_OF_MEM(cond);
diff --git a/source/libs/parser/src/parTranslater.c b/source/libs/parser/src/parTranslater.c
index 8eb79fe8aaac243a5408046aff33cd8a2abf21bf..9efc88d11b4273c34708cd3b3caf6c949e76053b 100644
--- a/source/libs/parser/src/parTranslater.c
+++ b/source/libs/parser/src/parTranslater.c
@@ -307,15 +307,6 @@ static EDealRes translateColumn(STranslateContext* pCxt, SColumnNode* pCol) {
   return found ? DEAL_RES_CONTINUE : translateColumnWithoutPrefix(pCxt, pCol);
 }
 
-static int32_t trimStringWithVarFormat(const char* src, int32_t len, bool format, char* dst) {
-  char* dstVal = dst;
-  if (format) {
-    varDataSetLen(dst, len);
-    dstVal = varDataVal(dst);
-  }
-  return trimString(src, len, dstVal, len);
-}
-
 static EDealRes translateValue(STranslateContext* pCxt, SValueNode* pVal) {
   if (pVal->isDuration) {
     char unit = 0;
@@ -355,26 +346,18 @@ static EDealRes translateValue(STranslateContext* pCxt, SValueNode* pVal) {
       case TSDB_DATA_TYPE_NCHAR:
       case TSDB_DATA_TYPE_VARCHAR:
       case TSDB_DATA_TYPE_VARBINARY: {
-        int32_t n = strlen(pVal->literal);
-        pVal->datum.p = calloc(1, n + VARSTR_HEADER_SIZE);
+        pVal->datum.p = calloc(1, pVal->node.resType.bytes + VARSTR_HEADER_SIZE);
         if (NULL == pVal->datum.p) {
           return generateDealNodeErrMsg(pCxt, TSDB_CODE_OUT_OF_MEMORY);
         }
-        trimStringWithVarFormat(pVal->literal, n, true, pVal->datum.p);
+        varDataSetLen(pVal->datum.p, pVal->node.resType.bytes);
+        strcpy(varDataVal(pVal->datum.p), pVal->literal);
         break;
       }
       case TSDB_DATA_TYPE_TIMESTAMP: {
-        int32_t n = strlen(pVal->literal);
-        char* tmp = calloc(1, n);
-        if (NULL == tmp) {
-          return generateDealNodeErrMsg(pCxt, TSDB_CODE_OUT_OF_MEMORY);
-        }
-        int32_t len = trimStringWithVarFormat(pVal->literal, n, false, tmp);
-        if (taosParseTime(tmp, &pVal->datum.i, len, pVal->node.resType.precision, tsDaylight) != TSDB_CODE_SUCCESS) {
-          tfree(tmp);
+        if (taosParseTime(pVal->literal, &pVal->datum.i, pVal->node.resType.bytes, pVal->node.resType.precision, tsDaylight) != TSDB_CODE_SUCCESS) {
           return generateDealNodeErrMsg(pCxt, TSDB_CODE_PAR_WRONG_VALUE_TYPE, pVal->literal);
         }
-        tfree(tmp);
         break;
       }
       case TSDB_DATA_TYPE_JSON:
diff --git a/source/libs/parser/src/sql.c b/source/libs/parser/src/sql.c
index 9312537c4901c8f7467a7d1cb3d3003180b07dde..806e7efc779c27fb1d42173cbd03be30800941ae 100644
--- a/source/libs/parser/src/sql.c
+++ b/source/libs/parser/src/sql.c
@@ -2284,8 +2284,14 @@ static YYACTIONTYPE yy_reduce(
 { pCxt->pRootNode = createShowStmt(pCxt, QUERY_NODE_SHOW_STREAMS_STMT, NULL, NULL); }
         break;
       case 101: /* db_name_cond_opt ::= */
-      case 103: /* like_pattern_opt ::= */ yytestcase(yyruleno==103);
       case 106: /* from_db_opt ::= */ yytestcase(yyruleno==106);
+{ yymsp[1].minor.yy68 = createDefaultDatabaseCondValue(pCxt); }
+        break;
+      case 102: /* db_name_cond_opt ::= db_name NK_DOT */
+{ yylhsminor.yy68 = createValueNode(pCxt, TSDB_DATA_TYPE_BINARY, &yymsp[-1].minor.yy5); }
+  yymsp[-1].minor.yy68 = yylhsminor.yy68;
+        break;
+      case 103: /* like_pattern_opt ::= */
       case 198: /* where_clause_opt ::= */ yytestcase(yyruleno==198);
       case 202: /* twindow_clause_opt ::= */ yytestcase(yyruleno==202);
       case 207: /* sliding_opt ::= */ yytestcase(yyruleno==207);
@@ -2295,10 +2301,6 @@ static YYACTIONTYPE yy_reduce(
       case 233: /* limit_clause_opt ::= */ yytestcase(yyruleno==233);
 { yymsp[1].minor.yy68 = NULL; }
         break;
-      case 102: /* db_name_cond_opt ::= db_name NK_DOT */
-{ yylhsminor.yy68 = createValueNode(pCxt, TSDB_DATA_TYPE_BINARY, &yymsp[-1].minor.yy5); }
-  yymsp[-1].minor.yy68 = yylhsminor.yy68;
-        break;
       case 104: /* like_pattern_opt ::= LIKE NK_STRING */
 { yymsp[-1].minor.yy68 = createValueNode(pCxt, TSDB_DATA_TYPE_BINARY, &yymsp[0].minor.yy0); }
         break;
diff --git a/source/libs/parser/test/parserAstTest.cpp b/source/libs/parser/test/parserAstTest.cpp
index 732e8ec0a7e773d6ca8e7e362f84df88a6faa724..20dcc3251d21a79b3df0f474a45eaa205157d4d0 100644
--- a/source/libs/parser/test/parserAstTest.cpp
+++ b/source/libs/parser/test/parserAstTest.cpp
@@ -409,11 +409,11 @@ TEST_F(ParserTest, createTable) {
 TEST_F(ParserTest, showTables) {
   setDatabase("root", "test");
 
-  // bind("show tables");
-  // ASSERT_TRUE(run());
+  bind("show tables");
+  ASSERT_TRUE(run());
 
-  // bind("show test.tables");
-  // ASSERT_TRUE(run());
+  bind("show test.tables");
+  ASSERT_TRUE(run());
 
   bind("show tables like 'c%'");
   ASSERT_TRUE(run());