Question

我正在尝试执行此SQL查询：

 SELECT field FROM table
 INTERSECT
 SELECT field FROM table

哪个返回给定字段的交集，但是我想从表中获取另一个字段（与给定字段相交），我该怎么做？

Answer 1

我会使用EXISTS子查询：

SELECT t1.OtherField
FROM Table1 t1
WHERE EXISTS (
        SELECT 1
        FROM Table2 t2
        WHERE t2.Field = t1.Field
    )

或者，您可以使用IN子查询，这可能在某些RDBMS或配置中更好用：

SELECT t1.OtherField
FROM Table1 t1
WHERE t1.Field IN (
        SELECT t2.Field
        FROM Table2 t2
    )

Answer 2

您可以使用IN。

SELECT c1
FROM a
WHERE c2 IN (
        SELECT x1
        FROM b
        );

示例：

表：a

c1 c2 ------ 1 10 2 20 3 30

表：b

x1 --- 20 30

<强>结果：

c1 -- 2 3

DEMO

Answer 3

这样的事情应该这样做：

查看joins

select 
    t1.AnyField, t2.AnyField
from 
    t1
    inner join t2 on t1.intersection_field = t2.intersection_field

根据你对同一张桌子的评论

select 
    t1.AnyField, t2.AnyField
from 
    table as t1
    inner join table as t2 on t1.intersection_field = t2.intersection_field
      and t1.another_field = t2.another_field

或

select 
    t1.AnyField, t2.AnyField
from 
    table as t1
    inner join table as t2 on t1.intersection_field = t2.intersection_field
where
    t1.filtered_field = 'text'
    and t2.yet_another_field >= 10

Answer 4

SELECT anotherField 
FROM table b
JOIN table1 a ON a.field=b.field

SQL INTERSECT由一个字段获取另一个字段

4 个答案: