Unknown column $user_id in WHERE clause

[WebMachine]

I am building an application for a charity in CodeIgniter 3, and have run into a problem trying to access the church name assigned to a given logged in user.

This is my method in the user_model.php:

/*
    * get church name for a given user
    */
    public function get_user_church($user_id) {

         // Test to make sure value of $user_id is being passed to this method
         // echo $user_id;
        //  exit;

    $query = $this->db->query(
                                'SELECT users.id, churches.name AS church_name
                                FROM users
                                JOIN churches ON users.church_id = churches.id
                                WHERE users.id = $user_id'        
                            );
                
        return $query->result();
        
    }

I tested the variable $user_id being passed into the method, and it is working ok, and this query works when I use the actual value of $user_id, but I get the above error message when I try to use $user_id.

It must be something simple that I’m not seeing, but I can’t figure out what it is. Any suggestions?

[fretburner]

You need to use double quotes to enclose your string, otherwise PHP will treat $user_id as text rather than replacing it with the variable’s value.

[WebMachine]

Of course! I knew it had to be something I should have seen, but was totally blind to. Thank you for responding so quickly!