Question

I am wondering if it is possible to alias 2 columns from 2 separate tables to the same name.

For example i want to join an email table with a user table and admin table and let the respective ‘name’ columns be combined in the same column.

Email Table: Email ID | Email Address

User Table: Username| Email ID

Admin Table: Username| Email ID

Result:

Username | Email Address

Answer 1

I believe this is what you’re trying to get:

SELECT a.Username, a.Email_ID, b.Email_Address
FROM
    (SELECT Username, Email_ID FROM User
    UNION ALL
    SELECT Username, Email_ID FROM Admin) a
INNER JOIN Email b ON b.Email_ID = a.Email_ID

This will stack the User and Admin tables and then JOIN the Email table.

Note that if there are duplicates and you want to remove them you should use UNION instead of UNION ALL.