Error Number: 1066 Not unique table/alias: 'service' in codeigniter - php

Question

Want to get all services in one to many relationship
My code is
$this->db->select('*');
$this->db->from('service');
$this->db->join('user', 'user.user_email = service.user_email', 'inner');
$this->db->join('service', 'service.user_email = user.user_email', 'inner');
$query = $this->db->get();
But it gives me an error
Error Number: 1066
Not unique table/alias: 'service'
SELECT * FROM (`service`) INNER JOIN `user` ON `user`.`user_email` = `service`.`user_email` INNER JOIN `service` ON `service`.`user_email` = `user`.`user_email`
Filename: C:\xampp\htdocs\service\system\database\DB_driver.php
If I do without
$this->db->from('service');
Then it gives syntax error
Error Number: 1064
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'INNER JOIN `user` ON `user`.`user_email` = `service`.`user_email` INNER JOIN `se' at line 2
SELECT * INNER JOIN `user` ON `user`.`user_email` = `service`.`user_email` INNER JOIN `service` ON `service`.`user_email` = `user`.`user_email`
Filename: C:\xampp\htdocs\service\system\database\DB_driver.php

Answer 1

You are trying to join the service table to the user table and then trying to join the service table again.
This isn't something you should generally be trying to do, and when you do it this way, the rendered SQL statement contains two attempts to reference the service table. It's the second JOIN that causes the database pain and it throws the error that you're seeing.
In this instance, just use:
$this->db->select('*');
$this->db->from('service');
$this->db->join('user', 'user.user_email = service.user_email', 'inner');
$query = $this->db->get();
Since the
$this->db->join('service', 'service.user_email = user.user_email', 'inner');
is redundant here (you've already joined these tables on that field.