Question

I’m trying to achieve the following in SQL Server 2005:

SELECT (IF EITHER EXISTS) usr.username, pro.email
FROM table1 AS usr, table2 AS pro
WHERE usr.username = 'existing_username'
AND / OR
pro.email = 'existing_email'

I can’t figure out how to write something like that. Basically I want it to return the username if it finds an existing one, and return the email if it finds one.

So it would return to me: username, email, both or none

Is this possible???

Answer 1

Its not really clear what you want. Since you’re not joining the tables I’m assuming you really want the union of the two

SELECT 
       usr.UserName foo
FROM
     table1 AS usr
WHERE
    usr.username = 'existing_username'
UNION ALL SELECT 
       pro.email foo
FROM
     table2 AS pro
WHERE
    pro.email = 'existing_email'

If you want to know where it came from you could do

SELECT 
       usr.UserName foo,
       'usr' source
FROM
     table1 AS usr
WHERE
    usr.username = 'existing_username'
UNION SELECT 
       pro.email foo
      'email' source
FROM
     table2 AS pro
WHERE
    pro.email = 'existing_email'