请问对以下的sql语句有没有解决办法?
select aa,sum(qty) as qtytotal from
(
select cc,qty from dd
union all
select ee,qty from ff
)a
group by aa
能不能把qtytotal=0的记录过滤掉???
[解决办法]
-- 注意是否会出现NULL值
CREATE TABLE DD(CC NCHAR(10),QTY INT)
INSERT DD SELECT 'AB ',0
INSERT DD SELECT 'CC ',5
SELECT * FROM DD
CREATE TABLE FF(EE NCHAR(10),QTY INT)
INSERT FF SELECT 'CC ',0
SELECT * FROM FF
SELECT AA,SUM(QTY) AS QTYTOTAL FROM
(
SELECT CC AS AA ,QTY FROM DD
UNION ALL
SELECT EE AS AA,QTY FROM FF
)A
GROUP BY AA
HAVING SUM(QTY) <> 0
DROP TABLE DD
DROP TABLE FF
