CodeIgniter unknown SQL error - database

Question

Here is my selection code from db:
$q = $this->db->like('Autor1' or 'Autor2' or 'Autor3' or 'Autor4', $vyraz)
->where('stav', 1)
->order_by('id', 'desc')
->limit($limit)
->offset($offset)
->get('knihy');
return $q->result();
Where $vyraz = "Zuzana Šidlíková";
And the error is:
Nastala chyba databázy
Error Number: 1054
Unknown column '1' in 'where clause'
SELECT * FROM (\knihy`) WHERE `stav` = 1 AND `1` LIKE '%Zuzana Šidlíková%' ORDER BY `id` desc LIMIT 9
Filename: C:\wamp\www\artbooks\system\database\DB_driver.php
Line Number: 330
Can you help me solve this problem?

Answer 1

Your syntax is wrong for what you're trying to do, but still technically valid, because this:
'Autor1' or 'Autor2' or 'Autor3' or 'Autor4'
...is actually a valid PHP expression which evaluates to TRUE (because all non-empty strings are "truthy"), which when cast to a string or echoed comes out as 1, so the DB class is looking to match on a column called "1".
Example:
function like($arg1, $arg2)
{
return "WHERE $arg1 LIKE '%$arg2%'";
}
$vyraz = 'Zuzana Šidlíková';
echo like('Autor1' or 'Autor2' or 'Autor3' or 'Autor4', $vyraz);
// Output: WHERE 1 LIKE '%Zuzana Šidlíková%'
Anyways, here's what you need:
$q = $this->db
->like('Autor1', $vyraz)
->or_like('Autor2', $vyraz)
->or_like('Autor3', $vyraz)
->or_like('Autor4', $vyraz)
->where('stav', 1)
->order_by('id', 'desc')
->limit($limit)
->offset($offset)
->get('knihy');