From 76638283b130e95be2f5dedde143903286c29a2b Mon Sep 17 00:00:00 2001
From: Haojun Liao <hjliao@taosdata.com>
Date: Mon, 7 Jun 2021 14:28:04 +0800
Subject: [PATCH] [td-225] fix compiler error.

---
 src/query/src/qAggMain.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/query/src/qAggMain.c b/src/query/src/qAggMain.c
index cdc1a67c06..0cb895709c 100644
--- a/src/query/src/qAggMain.c
+++ b/src/query/src/qAggMain.c
@@ -3730,7 +3730,7 @@ static void diff_function(SQLFunctionCtx *pCtx) {
         }
 
         if (pCtx->param[1].nType != INITIAL_VALUE_NOT_ASSIGNED) {  // initial value is not set yet
-          *pOutput = pData[i] - pCtx->param[1].dKey;  // direct previous may be null
+          *pOutput = (float)(pData[i] - pCtx->param[1].dKey);  // direct previous may be null
           *pTimestamp = tsList[i];
           pOutput    += 1;
           pTimestamp += 1;