I am doing a query, in which the second query can give "NULL" or a value (if there is data).
SELECT *, (SELECT tb1.image FROM ce_users_images tb1
WHERE tb1.iduser = users.iduser LIMIT 1) AS tmp1
FROM ce_users users
WHERE users.id_user=4
LIMIT 1
I want to return NULL in this second query, return a default value, otherwise it gives the value of the query.
I tried to use an IFNULL, but it always gives me error. Can you help with this in the query ??
You can use the function IFFNULL or COALESCE :
SELECT
users.*,
COALESCE(
(SELECT
tb1.image
FROM ce_users_images tb1
WHERE tb1.iduser = users.id_user
LIMIT 1),'Nenhuma imagem informada') AS tmp1
FROM ce_users users
WHERE users.id_user=4
LIMIT 1
A little more about the coalesce function: link
Since you want to return a field from a related table you can use JOIN to do this. In this case you need to return the contents of the ce_users table, regardless of whether there is a related record in the ce_users_images table LEFT JOIN would work very well.
SELECT
users.*, IFNULL(images.image,'img_default.jpg')
FROM
ce_users AS users
LEFT JOIN
ce_users_images AS images ON users.iduser = images.iduser
WHERE
users.id_user = 4
If there is more than one record listed in the table you can use the GROUP BY clauses or add filters in the WHERE or ON clauses.