记账软件版1楼: 我现在要查询三个表b1,b2,b3,用左连接查询:select a.id,b.wegit,c.weight from b1 as a left join b2 as b left join b3 as c on a.id=b.id and a.id=c.id,但执行时,说条件语句有错,整个语句该怎么写请各位高手指教!!,急救,多谢!!!

2楼: select a.id,b.wegit,c.weight from b1 as a,b2 as b,b3 as c,
a left join b on a.id=b.id,
a left join c on a.id=c.id 如会计电算化软件下载

3楼: select a.id,b.wegit,c.weight from b1 as a left outer join b2 as b
on a.id=b.id
left outer join b3 as c on b.id=c.id

4楼: select a.id,b.wegit,c.weight from b1 as a
left outer join b2 as b on a.id=b.id
left outer join b3 as c on a.id=c.id

5楼: 少了 ON 连接条件

6楼: 都一樣,你們都說了,我沒有別的可說了