diff --git a/src/plugins/http/src/httpGcJson.c b/src/plugins/http/src/httpGcJson.c
index f33a994465a94bad5d79df8af73ff4fd9d640516..2d361d37940a93c3627ef53883a342d12183e6a1 100644
--- a/src/plugins/http/src/httpGcJson.c
+++ b/src/plugins/http/src/httpGcJson.c
@@ -199,7 +199,7 @@ bool gcBuildQueryJson(HttpContext *pContext, HttpSqlCmd *cmd, TAOS_RES *result,
 
     for (int32_t i = dataFields; i >= 0; i--) {
       httpJsonItemToken(jsonBuf);
-      if (row[i] == NULL) {
+      if (row == NULL || i >= num_fields || row[i] == NULL) {
         httpJsonOriginString(jsonBuf, "null", 4);
         continue;
       }