transaction not returning false msg - php

Question

I am trying to update 3 tables using transaction if any one fails I need to roll back all the tables. For one table foreign key constraint fails but it does not return false statement instead showing console error of Database. Roll back is working. I include my code below. Kindly help.
The function below helps me to execute some queries
function funcname($val1,$val2,$val3){
$this->db->trans_start();//starting transaction
try { // trying to execute query
$this->db->query("UPDATE tab1 SET name = 1 WHERE id=".$val1);
$this->db->query("UPDATE school SET emp = 2 WHERE id=".$val2);
$this->db->query("UPDATE profile SET status = 4 WHERE id=".$val3);
$this->db->trans_complete();
return TRUE;
} catch (Exception $ex) { //exception roll back to original state
$this->db->trans_rollback();
return FALSE;
}
}

Answer 1

If you are using trans_start() and trans_complete() then you need not use a try catch statement. Your function will be like this.
function funcname($val1,$val2,$val3){
$this->db->trans_start();//starting transaction
$this->db->query("UPDATE tab1 SET name = 1 WHERE id=".$val1);
$this->db->query("UPDATE school SET emp = 2 WHERE id=".$val2);
$this->db->query("UPDATE profile SET status = 4 WHERE id=".$val3);
$this->db->trans_complete();
if ($this->db->trans_status() === FALSE)
{
return FALSE;
}
else
{
return TRUE;
}
}
In case you need to do it manually then use the code below
function funcname($val1,$val2,$val3){
$this->db->trans_begin();//starting transaction
$this->db->query("UPDATE tab1 SET name = 1 WHERE id=".$val1);
$this->db->query("UPDATE school SET emp = 2 WHERE id=".$val2);
$this->db->query("UPDATE profile SET status = 4 WHERE id=".$val3);
if ($this->db->trans_status() === FALSE)
{
$this->db->trans_rollback();
return FALSE;
}
else
{
$this->db->trans_commit();
return TRUE;
}
}
for more reference Transactions : CodeIgniter User Guide

Answer 2

I don't know how your db class works, but probably query return false on fails not throw Exception, so trans_complete() return false too, and then your function return TRUE