diff --git a/src/client/src/tscFunctionImpl.c b/src/client/src/tscFunctionImpl.c
index caaedca1f297a91fde376d41f2f63be118c43618..9995f94dbe47aa2f3861e5b4134f792750701092 100644
--- a/src/client/src/tscFunctionImpl.c
+++ b/src/client/src/tscFunctionImpl.c
@@ -2965,14 +2965,28 @@ static void tag_project_function(SQLFunctionCtx *pCtx) {
   assert(pCtx->inputBytes == pCtx->outputBytes);
   
   for (int32_t i = 0; i < pCtx->size; ++i) {
-    tVariantDump(&pCtx->tag, pCtx->aOutputBuf, pCtx->outputType);
+    char* output = pCtx->aOutputBuf;
+  
+    if (pCtx->tag.nType == TSDB_DATA_TYPE_BINARY || pCtx->tag.nType == TSDB_DATA_TYPE_NCHAR) {
+      *(int16_t*) output = pCtx->tag.nLen;
+      output += VARSTR_HEADER_SIZE;
+    }
+    
+    tVariantDump(&pCtx->tag, output, pCtx->outputType);
     pCtx->aOutputBuf += pCtx->outputBytes;
   }
 }
 
 static void tag_project_function_f(SQLFunctionCtx *pCtx, int32_t index) {
   INC_INIT_VAL(pCtx, 1);
-  tVariantDump(&pCtx->tag, pCtx->aOutputBuf, pCtx->tag.nType);
+  
+  char* output = pCtx->aOutputBuf;
+  if (pCtx->tag.nType == TSDB_DATA_TYPE_BINARY || pCtx->tag.nType == TSDB_DATA_TYPE_NCHAR) {
+    *(int16_t*) output = pCtx->tag.nLen;
+    output += VARSTR_HEADER_SIZE;
+  }
+  
+  tVariantDump(&pCtx->tag, output, pCtx->tag.nType);
   pCtx->aOutputBuf += pCtx->outputBytes;
 }
 
@@ -3007,7 +3021,8 @@ static void tag_function_f(SQLFunctionCtx *pCtx, int32_t index) {
     *(int16_t*) output = pCtx->tag.nLen;
     output += VARSTR_HEADER_SIZE;
   }
-  tVariantDump(&pCtx->tag, pCtx->aOutputBuf, pCtx->tag.nType);
+  
+  tVariantDump(&pCtx->tag, output, pCtx->tag.nType);
 }
 
 static void copy_function(SQLFunctionCtx *pCtx) {
diff --git a/src/client/src/tscSQLParser.c b/src/client/src/tscSQLParser.c
index cf4aa3a50d2af09c8602882693bdae06de1232a3..e23086c4e7f8c8b4bd559eeb2756460a083719d1 100644
--- a/src/client/src/tscSQLParser.c
+++ b/src/client/src/tscSQLParser.c
@@ -5132,7 +5132,7 @@ static int32_t doAddGroupbyColumnsOnDemand(SQueryInfo* pQueryInfo) {
     int16_t colIndex = pColIndex->colIndex;
     if (colIndex == TSDB_TBNAME_COLUMN_INDEX) {
       type = TSDB_DATA_TYPE_BINARY;
-      bytes = TSDB_TABLE_NAME_LEN;
+      bytes = TSDB_TABLE_NAME_LEN + VARSTR_HEADER_SIZE; // todo extract method
       name = TSQL_TBNAME_L;
     } else {
       if (TSDB_COL_IS_TAG(pColIndex->flag)) {
diff --git a/src/client/src/tscUtil.c b/src/client/src/tscUtil.c
index d07185b0ba798060818e86bd0160ad279ff6bf36..4844ab3db86bdaa25700a5b759cf2d4ea61527d9 100644
--- a/src/client/src/tscUtil.c
+++ b/src/client/src/tscUtil.c
@@ -2134,7 +2134,7 @@ char* tscGetResultColumnChr(SSqlRes* pRes, SQueryInfo* pQueryInfo, int32_t colum
   if (type == TSDB_DATA_TYPE_NCHAR || type == TSDB_DATA_TYPE_BINARY) {
     int32_t realLen = varDataLen(pData);
     if (realLen < pInfo->pSqlExpr->resBytes - VARSTR_HEADER_SIZE) { // todo refactor
-      *(char*) (pData + realLen + sizeof(int16_t)) = 0;
+      *(char*) (pData + realLen + VARSTR_HEADER_SIZE) = 0;
     }
     
     return pData + VARSTR_HEADER_SIZE; // head is the length of binary/nchar data
diff --git a/src/query/src/queryExecutor.c b/src/query/src/queryExecutor.c
index ed0da791dc67cee130ebae13dba203a8cd7aa3b3..e8abe9d81938286edec6e605476893da4dd12d9f 100644
--- a/src/query/src/queryExecutor.c
+++ b/src/query/src/queryExecutor.c
@@ -1427,7 +1427,7 @@ static int32_t setupQueryRuntimeEnv(SQueryRuntimeEnv *pRuntimeEnv, int16_t order
     int32_t index = pSqlFuncMsg->colInfo.colIndex;
     if (TSDB_COL_IS_TAG(pIndex->flag)) {
       if (pIndex->colId == TSDB_TBNAME_COLUMN_INDEX) {
-        pCtx->inputBytes = TSDB_TABLE_NAME_LEN;
+        pCtx->inputBytes = TSDB_TABLE_NAME_LEN + VARSTR_HEADER_SIZE;
         pCtx->inputType = TSDB_DATA_TYPE_BINARY;
       } else {
         pCtx->inputBytes = pQuery->tagColList[index].bytes;
@@ -5528,7 +5528,7 @@ static int32_t createSqlFunctionExprFromMsg(SQueryTableMsg *pQueryMsg, SExprInfo
       bytes = tDataTypeDesc[type].nSize;
     } else if (pExprs[i].base.colInfo.colId == TSDB_TBNAME_COLUMN_INDEX) {  // parse the normal column
       type  = TSDB_DATA_TYPE_BINARY;
-      bytes = TSDB_TABLE_NAME_LEN;
+      bytes = TSDB_TABLE_NAME_LEN + VARSTR_HEADER_SIZE;
     } else{
       int32_t j = getColumnIndexInSource(pQueryMsg, &pExprs[i].base, pTagCols);
       assert(j < pQueryMsg->numOfCols || j < pQueryMsg->numOfTags);