联合查询问题

[global_boy]

select tusers_t.* from tusers,tusers_t where tusers_t.scardid=tusers.scardid;
以上语句可以实现查询表tusers_t和表tusers字段scardid相同的数据；

请问如何查询表tusers_t有，而表tusers没有的scardid？

[GRLD8888]

请问如何查询表tusers_t有，而表tusers没有的scardid？

select a.scardid,b.scardid from tusers_t a left join tusers b on a.scardid=b.scardid where b.scardid is null

[lovewindy]

select tusers_t.* from tusers_t where scardid not in (select scardid from tusers)

好像这样也可以吧,

[fhuibo]

select tusers_t.* from tusers,tusers_t where tusers_t.scardid<>tusers.scardid

[tangqijun199]

select tusers_t.* from tusers_t b left join tusers a on b.scardid=a.scardid;
where a.主键 is null

[QQMagicer]

select *
from tusers_t
where tusers_t.scardid not in(select tusers.scardid from tusers)

[kadeya]

select scardid
from tusers_t
where scardid not in (select scardid from tusers)