如何使用 sql 连接两个表并创建一个新表以检查哪个表值存在

Question

I am trying to join two tables and create a new table to check in which table value exists using sql

Table A

Student ID   Name
1            abcd
2            efgh
3            ijkl
4            mnop
5            erst
6            uvwx

Table B

Student ID   Name
1            qwer
2            west
3            ijkl
4            mnop
7            ikjh
8            iolk

Output To Be

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

Please let me know how this can be achieved using SQL.

Thank you in advance !

Answer 1

This sounds like 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)