[英]How to join two tables and create a new table to check in which table value exists using sql
我正在尝试连接两个表并创建一个新表以使用 sql 检查存在哪个表值
表 A
Student ID Name
1 abcd
2 efgh
3 ijkl
4 mnop
5 erst
6 uvwx
表 B
Student ID Name
1 qwer
2 west
3 ijkl
4 mnop
7 ikjh
8 iolk
Output 待定
Student ID Name New Column
1 abcd Present in A
2 efgh Present in A
3 ijkl Both
4 mnop Both
5 erst Present in A
6 uvwx Present in A
7 ikjh Present in B
8 iolk Present in B
请让我知道如何使用 SQL 来实现。
先感谢您 !
这听起来像FULL JOIN
:
select id, name,
(case when a.id is not null and b.id is not null then 'Both'
when a.id is not null then 'A Only'
else 'B Only'
end) as new_column
from a full join
b
using (id, name)
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.