Question

I have a user table ‘users’ that has fields like:

id
first_name
last_name
...

and have another table that determines relationships:

user_id
friend_id
user_accepted
friend_accepted
....

I would like to generate a query that selects all the users but also add another field/column say ‘network_status’ that depends on the values of user_accepted and fiend_accepted. For example, if user_accepted is true friend_accepted is false I want the ‘network_status’ field to say ‘request sent’. Can I possibly do this in one query? (I would prefer not to user if/else inside the query but if that’s the only way so be it)

Answer 1

You will have to take a look at CASE Statement

Something like

SELECT  u.id,
        u.first_name,
        u.last_name,
        CASE 
            WHEN r.user_accepted = 1 AND r.friend_accepted = 0
                THEN 'request sent'
            ELSE 'Not sure'
        END
FROM    users u LEFT JOIN
        relationships r ON u.id = r.user_id