Question

This are the tables that are used in the querys:

HELPS (Fields relevant: id, id_user)

FRIENDS

SHARED_HELPS

So:

This query (works) returns al the helps from a user and all from other users that he referenced:

$sql = 'SELECT
                      helps.*,CASE WHEN shared_helps.userid IS NULL THEN 0 ELSE shared_helps.userid END as is_shared, CASE WHEN shared_helps.userid IS NULL THEN helps.fecha ELSE shared_helps.fecha END as ffecha
                    FROM
                      helps
                    LEFT JOIN  shared_helps
                        ON  shared_helps.helpid = helps.id
                        AND shared_helps.userid = '.$value.'

                    WHERE     (helps.id_user = '.$value.' AND helps.id_group <= 0)  OR shared_helps.userid = '.$value.'



                   ORDER BY ffecha DESC';

Also, this query (works) lists all the helps from a user an the ones from his friends

$sql = 'SELECT  id, title, content, id_user, id_group, id_type, id_loc, avatar, attached, fecha, likes, lan, needsCount, recivedCount
                    FROM
                        (
                            SELECT *, 1 as OrderBy           
                                FROM helps 
                             WHERE id_user = '.$value.' or id_user IN (SELECT helpid FROM shared_helps WHERE userid = '.$value.')
                            UNION
                            SELECT  h.*, 2 as OrderBy        
                                 FROM    (
                                        SELECT  id  AS friendsId,
                                                CASE followerid 
                                                    WHEN '.$value.' THEN followingid 
                                                    ELSE followerid 
                                                END AS friend_id
                                        FROM    friends
                                        WHERE   acepted = 1 AND 
                                                (followerid  ='.$value.' OR followingid = '.$value.')
                                    ) AS f
                                        INNER JOIN helps AS h 
                                            ON h.id_user = f.friend_id where id_group < 0
                        ) x
                    ORDER BY ID DESC
                    ';

The thing is to the last one, i need to add the ones that are from other users but he referenced (is like a mix of the two query I posted..)

I tried this:

$sql = 'SELECT  id, title, content, id_user, id_group, id_type, id_loc, avatar, attached, fecha, likes, lan, needsCount, recivedCount,
                            CASE WHEN shared_helps.userid IS NULL THEN helps.fecha ELSE shared_helps.fecha END as ffecha
                    FROM
                        (
                            SELECT *, 1 as OrderBy           
                                FROM helps 
                             WHERE id_user = '.$value.' or id_user IN (SELECT helpid FROM shared_helps WHERE userid = '.$value.')
                            UNION
                            SELECT  h.*, 2 as OrderBy        
                                 FROM    (
                                        SELECT  id  AS friendsId,
                                                CASE followerid 
                                                    WHEN '.$value.' THEN followingid 
                                                    ELSE followerid 
                                                END AS friend_id
                                        FROM    friends
                                        WHERE   acepted = 1 AND 
                                                (followerid  ='.$value.' OR followingid = '.$value.')
                                    ) AS f
                                        INNER JOIN helps AS h 
                                            ON h.id_user = f.friend_id where id_group < 0
                        ) x
                    LEFT JOIN  shared_helps
                            ON  shared_helps.helpid = x.id
                            AND shared_helps.userid = '.$value.'

                        WHERE     (x.id_user = '.$value.' AND helps.id_group <= 0)  OR shared_helps.userid = '.$value.'



                    ORDER BY ffecha DESC
                    ';

But i got:

Column 'id' in field list is ambiguous

But this is obviously out of my knowledge.. Can anyone show me the ligth?

Answer 1

if I’m not mistaken, you need to specify where column ID does it come from because all tables has column ID.

Try adding the tableName Helps and since it contains in a subquery x

SO in your query,

SELECT x.ID, ....
FROM...
WHERE ....