mysql - 选择 1 - 选择 2

Question

在查询中，
select id,name,feature,marks from (....)
我想删除其 id 在另一个 select 语句中存在的那些。
从 (...) 中选择 id

我是 sql 新手。是否有直接执行此操作的语句？

Answer 1

几种方法。

Join:

select t1.id, t1.name, t1.feature, t1.marks 
from t1
left outer join (some select statement) t2
on t1.id = t2.id
where t2.id is null

Antijoin:

select t1.id, t1.name, t1.feature, t1.marks 
from t1
where not exists (
   select id 
   from (some select statement) t2 
   where t2.id = t1.id
)

"Not In":

select t1.id, t1.name, t1.feature, t1.marks 
from t1
where t1.id not in (
   select id 
   from (some select statement)
)