统计过程处理NULL字段
现在一个数据表A， 有字段rwhao(nvarchar), net(decimal) ,现在要按 rwhao来分组统计net ,如果net 统计结果为NULL,则显示为0 ，如何统计
我这统计不显示
SELECT RWHao, COALESCE (SUM(NET), 0) AS tj
FROM dbo.tbDBDataHj AS B
GROUP BY RWHao
[解决办法]
isnull(NET,0)
[解决办法]
SELECT RWHao, isnull(SUM(NET), 0) AS tj
FROM dbo.tbDBDataHj AS B
GROUP BY RWHao
[解决办法]
楼主你这样有点小题大做了，

SELECT  RWHao ,
        ISNULL(SUM(NET), 0) AS tj
FROM    dbo.tbDBDataHj AS B
GROUP BY RWHao

COALESCE 函数的确很有用，比isnull有用的多：
一个非常有用的函数——COALESCE
[解决办法]
SELECT RWHao, COALESCE (SUM(ISNULL(NET,0)), 0) AS tj
FROM dbo.tbDBDataHj AS B
GROUP BY RWHao