Question

I have two tables i.e.

Invitation

• InvitationID
• UserID
• Email

Users

• UserID
• Username

I have data in both table

Invitation table data

29  NULL    [e-mail]   
40  8       [e-mail]                                                                       
41  8       [e-mail]     

Users table data

8     [e-mail]

Now I want to select all data from the Invitation table, and also want to select Username from Users table where Invitation.InvitationID is equal to Users.UserID.

I use this following query to select data

SELECT 
    Invitations.*, Users.UserName
FROM
    Invitations 
INNER JOIN
    Users ON Invitations.UserID = Users.UserID

But it returns only two rows. I want to select all rows from the Invitation table. If Invitation.UserID is null then Username is also null. I want output like this:

 29  NULL   [e-mail]   Null
 40  8      [e-mail]   [e-mail]                                                                  
 41  8      [e-mail]   [e-mail] 

Answer 1

You have to use left join :

SELECT Invitations.*, Users.UserName
FROM     Invitations left JOIN
              Users ON Invitations.UserID = Users.UserID