Question

我有两张表ALLUSER和BLACKLISTNUMBER

select tel_number, telnumber_id, from alluser

如何选择号码是否在黑名单中？

Answer 1

不使用：

   select tel_number, telnumber_id, from alluser
   where tel_number not in 
  ( select tel_number from BLACKLISTNUMBER where 
   tel_number  is not null  )

Answer 2

使用not in之类的内容：

select tel_number, telnumber_id from alluser
where tel_number not in (select tel_number from blacklist);

或者可能是NOT EXISTS：

select tel_number, telnumber_id from alluser t
where not exists (select tel_number from blacklist where tel_number = t.tel_number);

Answer 3

很多方法可以实现这一目标。您也可以使用联接...

select    a.tel_number,
          a.telnumber_id
from      alluser         a
left join blacklist       b     on  a.tel_number = b.tel_number
where     b.tel_number is null

如何从带有检查的表中选择是否存在于另一个表中？

3 个答案: