sql 条件查询"奇异"地方，帮解决啊
SELECT sl.sid FROM modoer_coupons c LEFT JOIN modoer_subjectlink sl ON c.couponid = sl.flagid WHERE city_id IN (0,1) AND sl.flag = 'coupon' ORDER BY c.status LIMIT 1, 10

有结果

SELECT sl.sid FROM modoer_coupons c LEFT JOIN modoer_subjectlink sl ON c.couponid = sl.flagid WHERE city_id IN (0,1) AND sl.sid=732 AND sl.flag = 'coupon' ORDER BY c.status LIMIT 1, 10

没有结果

SELECT sl.sid FROM modoer_coupons c LEFT JOIN modoer_subjectlink sl ON c.couponid = sl.flagid WHERE city_id IN (0,1) AND sl.sid!=732 AND sl.flag = 'coupon' ORDER BY c.status LIMIT 1, 10

有结果

SELECT sl.sid FROM modoer_coupons c LEFT JOIN modoer_subjectlink sl ON c.couponid = sl.flagid WHERE sl.sid='731' ORDER BY c.status LIMIT 1, 10

没有结果

SELECT sl.sid FROM modoer_coupons c LEFT JOIN modoer_subjectlink sl ON c.couponid = sl.flagid WHERE sl.sid!='731' ORDER BY c.status LIMIT 1, 10

有结果
求助啊






------解决方案--------------------

SQL code

SELECT sl.sid FROM modoer_coupons c 
LEFT JOIN modoer_subjectlink sl ON c.couponid = sl.flagid AND sl.flag = 'coupon'
WHERE city_id IN (0,1)  ORDER BY c.status LIMIT 1, 10

------解决方案--------------------
LIMIT 1, 10

是MYSQL的吧。

------解决方案--------------------

ta
id  
1
2

tb
id sid
1  555
3  732

select a.*,b.* from ta a left join tb b on a.id= b.id where b.sid=732
在left join之后
第tb的第二行(id=3)未能连接，  ta作为左输入，全部保留， tb第一行右输入会有输出,第二行右输出为null
然后where
b.sid=732,  两行全被过滤， 自然没结果。

其实你的很简单，
不要加sid=732的条件，在navicat mysql客户端中， 仅取左联，  看结果， 或者然后在结果中再继续过滤 sid=732的记录，看看有没有值就是了。