laravel 5.4 how to handle query exception with custom exception - laravel

Question

whenever I try to delete an artist with the related song in the child table.
it returns this error.
QueryException in Connection.php line 647:
SQLSTATE[23000]: Integrity constraint violation: 1451 Cannot delete or update a parent row: a foreign key constraint fails (`laravel`.`artist_song`, CONSTRAINT `artist_song_artist_id_foreign` FOREIGN KEY (`artist_id`) REFERENCES `artists` (`id`)) (SQL: delete from `artists` where `id` = 1)
this is what I want. to protect the parent table, but what I want is to make the end user see a message saying like this "yOU CAN NOT DELETE AN ARTIST WITH RELATED SONGS PLEASE DELETE ALL SONGS OF THIS ARTIST, FIRST'. so how can I catch this with the custom exception?

Answer 1

I don't think you need to rely here on database exception. When someone chooses deleting artist you should verify whether artist has any songs and if yes, you should then redirect with message.
Assuming you have in Artist model relationship defined like this:
public function songs()
{
return $this->hasMany(Song::class);
}
in controller you could use code like this:
public function destroy($artistId)
{
$artist = Artist::findOrFail($artistId);
if ($artist->songs()->count()) {
return redirect()->back()->with('message','You cannot delete ...');
}
$artist->delete();
return redirect()->route('artists.index');
}