diff --git a/src/client/src/tscUtil.c b/src/client/src/tscUtil.c
index 4f04a82549..080ef9f2d2 100644
--- a/src/client/src/tscUtil.c
+++ b/src/client/src/tscUtil.c
@@ -71,7 +71,7 @@ void tsSetSTableQueryCond(STagCond* pTagCond, uint64_t uid, SBufferWriter* bw) {
 }
 
 bool tscQueryTags(SQueryInfo* pQueryInfo) {
-  int32_t numOfCols = (int32_t)(pQueryInfo);
+  int32_t numOfCols = (int32_t) tscSqlExprNumOfExprs(pQueryInfo);
   for (int32_t i = 0; i < numOfCols; ++i) {
     SSqlExpr* pExpr = tscSqlExprGet(pQueryInfo, i);
     int32_t functId = pExpr->functionId;