查出A的catelogid,查出C的catelogname是吗?可以用表连接来查,oracle: select a.catelogid,c.catelogname from A a join B b on a.catelogid=b.catelogid join C c on b.catelogname=c.catelogname; 不知道对不对,我也没试,我是初学者,希望有不对的多多指教
是postgresql的 2楼的试过了 还行不行 [SQL] select a.catelogid,c.catelogname from sir_dire_dictionary a join sir_dire_layer b on a.catelogid=b.catelogid join sir_layermetadata c on b.catelogname=c.catelogname[Err] ERROR: column a.catelogid does not exist LINE 2: ...om sir_dire_dictionary a join sir_dire_layer b on a.catelogi...
select a.*,c.* from A a join B b on a.catalogid = b.catalogid join C c on b.catalogname = c.catalogname不过话说你这表设计不行哦
sir_dire_dictionary表里到底有catelogid字段没?
select a.*,c.* from A a,B b,C c where a.catalogid = b.catalogid and b.catalogname = c.catalogname
select a.catelogid,c.catelogname from A a join B b on a.catelogid=b.catelogid
join C c on b.catelogname=c.catelogname;
不知道对不对,我也没试,我是初学者,希望有不对的多多指教
[SQL]
select a.catelogid,c.catelogname from sir_dire_dictionary a join sir_dire_layer b on a.catelogid=b.catelogid
join sir_layermetadata c on b.catelogname=c.catelogname[Err] ERROR: column a.catelogid does not exist
LINE 2: ...om sir_dire_dictionary a join sir_dire_layer b on a.catelogi...
join B b on a.catalogid = b.catalogid
join C c on b.catalogname = c.catalogname不过话说你这表设计不行哦
where a.catalogid = b.catalogid
and b.catalogname = c.catalogname