在codeigniter 3中切换数据库

Question

I am trying to use / change the database for different organizations / users. In master database, I have db_name for different organizations, I am using the following code to store the db_name in session.

$condition = "subdomain =" . "'" . $data['subdomain'] . "' AND " . "status =1";

$this->db->select('id, db_name');
$this->db->from('sublogin');
$this->db->where($condition);
$this->db->limit(1);

$db_name = $this->db->get()->row()->db_name;

// SET db_name for session
$this->session->set_userdata('db_name', $db_name);

in another model, switch the database

$db_name = $this->session->userdata('db_name');
$this->db->db_select($db_name); 

Its working on localhost but not on my live server, it gives error:

A Database Error Occurred Error Number: 1146 Table 'db694230824.users' doesn't exist

I tried to echo the current database and it says the database is not changed.

echo $this->db->database;
die(); 

Answer 1

1 solution.

You can work with multiple databases like this:

$this->db = $this->load->database('default', TRUE);
$this->anotherDb = $this->load->database('anotherDb ', TRUE);

Or if you assign the codeigniter super-object:

public function __construct($params) {

   $this->CI = & get_instance();
   $this->CI->db = $this->CI->load->database('default', TRUE);
   $this->CI->anotherDb = $this->CI->load->database('anotherDb', TRUE);
}

2 solution

It was working earlier, not 100% sure if it still works, but looks like this bug still exist in CI. Just add 1 line of code at simple_query function in /system/database/DB_driver.php file:

public function simple_query($sql)
{
    if ( ! $this->conn_id)
    {
        $this->initialize();
    }

    $this->db_select(); // add this
    return $this->_execute($sql);
}

It should allow you use other databases in models like this:

$this->anotherDb = $this->load->database('anotherDb', true);

Don't forget to add other's DBs CONNECTIVITY SETTINGS in /application/config/database.php file in similar way as you have with your default db:

$db['default'] = array(
    'dsn'   => '',
    'hostname' => 'localhost',
    ...
);

$db['anotherDb'] = array(
    'dsn'   => '',
    'hostname' => 'localhost',
    ...
);

CodeIgniter » Docs » Database Reference » Connecting to your Database