Select where not exists pdo - php

Question

I have a query
SELECT *
FROM `user`
WHERE NOT
EXISTS (
SELECT *
FROM roleInEvent
WHERE user.userId = roleInEvent.userId
AND eventId = 1
)
AND user.disciplineId =5
Whenever I run this in my mysql console it returns 1 row. This is correct.
However in my php script it returns zero rows while it is exact the same query.
My php script looks like this:
$db = DatabaseHelper::get();
$st = $db->prepare('SELECT *
FROM `user`
WHERE NOT
EXISTS (
SELECT *
FROM roleInEvent
WHERE user.userId = roleInEvent.userId
AND eventId = 1
)
AND user.disciplineId =5');
$st->execute();
if ($st->errorCode() !== \PDO::ERR_NONE) {
return null;
}
Somebody knows what is the problem here?

Answer 1

The solution was easy.
I forgot to return the results to my javascript

Answer 2

You can use too the IN with a NOT like:
SELECT * FROM user WHERE id_user NOT IN ( SELECT other_data FROM roleInEvent WHERE user.userId = roleInEvent.userId AND eventId = 1 ) AND user.disciplineId =5
If the query: SELECT other_data FROM roleInEvent WHERE user.userId = roleInEvent.userId AND eventId = 1 bring to you something, this result not have to exist in the user table.
Other example is:
Users Table:
---------------------------
id_user | name_user
1 fernando
2 urban
And in other table we have the block users:
Block Users:
id_user_block | id_user | name_user
1 1 fernando
2 2 john lennon
So,i want bring to me only users that not exists in the block users table:
The query will be:
SELECT * FROM Users WHERE id_user NOT IN ( SELECT id_user FROM blocked_users )
So, the last query we are getting:
id_user | name_user
2 john lennon
Greetings!