一个表a【username】一个表b【username,company,product】我想同时查找a,b这两个表让a的username等于b的usernameselect *
from a,b
where a.username= b.username这样的结果,会有很多重复的company请教如果同时保证company不重复呢???
from a,b
where a.username= b.username这样的结果,会有很多重复的company请教如果同时保证company不重复呢???
from a,b
where a.username= b.username
from a,b
where a.username= b.username
贴建表及插入记录的SQL,及要求结果出来看看
FROM b
LEFT JOIN a AS a ON a.username=b.username
WHERE a.username=b.username
from a,b
where a.username= b.username