SQL从两个表中获取公共行

Question

我有两个表T1和T2。

任何人都可以帮助一个SQL查询，它将从这两个表中获取通用行吗？ （假设T1和T2各有100列）

P.S：我猜INNER JOIN在每一列上都不是一个好主意。

感谢

Answer 1

select 
    t1.* 
from 
    t1, t2 
where 
(
    (t1.col1 is null and t2.col1 is null) or (
    (t1.col1   = t2.col1  ) 
) and 
(
    (t1.col2 is null and t2.col2 is null) or (
    (t1.col2   = t2.col2  ) 
) and 
(
    (t1.col3 is null and t2.col3 is null) or (
    (t1.col3   = t2.col3  ) 
) and 
.... 
(
    (t1.col100 is null and t2.col100 is null) or (
    (t1.col100   = t2.col100  ) 
) 

Answer 2

使用INTERSECT

SELECT * FROM T1 
INTERSECT 
SELECT * FROM T2 

Answer 3

如果您在使用SQL Server 2005，那么你可以使用相交关键词，它给你共同记录。

SELECT column1 
FROM table1 
INTERSECT 
SELECT column1 
FROM table2 

如果您希望在输出中同时来自两个表中具有公共列1的表1的column1和column2。

SELECT column1, column2 
FROM table1 
WHERE column1 IN 
(
SELECT column1 
FROM table1 
INTERSECT 
SELECT column1 
FROM table2 
)