我们能否在运行时根据codeigniter中的用户登录连接到数据库？

Question

I am working on project,where i want to connect to database at run time depending on user login.As i am starting my project now,i wanted to try out code-igniter framework.But after doing research ,i am finding it hard to say that this is possible.Else i have code for doing same in standard php. But i wanted to try framework before going for that approach. i have code for multiple ( 2 database ) connection.

$db['default']['hostname'] = 'localhost';
$db['default']['username'] = 'root';
$db['default']['password'] = '';
$db['default']['database'] = 'test1';
$db['default']['dbdriver'] = 'mysql';
$db['default']['dbprefix'] = '';
$db['default']['pconnect'] = TRUE;
$db['default']['db_debug'] = TRUE;
$db['default']['cache_on'] = FALSE;
$db['default']['cachedir'] = '';
$db['default']['char_set'] = 'utf8';
$db['default']['dbcollat'] = 'utf8_general_ci';
$db['default']['swap_pre'] = '';
$db['default']['autoinit'] = TRUE;
$db['default']['stricton'] = FALSE;

//Another database connection.

$db['db2']['hostname'] = 'localhost';
$db['db2']['username'] = 'root';
$db['db2']['password'] = '';
$db['db2']['database'] = 'test2';
$db['db2']['dbdriver'] = 'mysql';
$db['db2']['dbprefix'] = '';
$db['db2']['pconnect'] = FALSE;
$db['db2']['db_debug'] = TRUE;
$db['db2']['cache_on'] = FALSE;
$db['db2']['cachedir'] = '';
$db['db2']['char_set'] = 'utf8';
$db['db2']['dbcollat'] = 'utf8_general_ci';
$db['db2']['swap_pre'] = '';
$db['db2']['autoinit'] = TRUE;
$db['db2']['stricton'] = FALSE;

Answer 1

from the doc
To connect manually to a desired database you can pass an array of values:

$config['hostname'] = 'localhost';
$config['username'] = 'myusername';
$config['password'] = 'mypassword';
$config['database'] = 'mydatabase';
$config['dbdriver'] = 'mysqli';
$config['dbprefix'] = '';
$config['pconnect'] = FALSE;
$config['db_debug'] = TRUE;
$config['cache_on'] = FALSE;
$config['cachedir'] = '';
$config['char_set'] = 'utf8';
$config['dbcollat'] = 'utf8_general_ci';
$this->load->database($config);

Answer 2

Select the database in run time in codeigniter using the following statement.

$this->db->db_select('database2_name');

If you want to close the current connection then use

$this->db->close();//closes the current db connection

Then select the database you have required.

Answer 3

https://www.codeigniter.com/user_guide/database/connecting.html

Check out the section "Manually Connecting to a Database" where it says

To choose a specific group from your config file you can do this:

$this->load->database('group_name');

So after logging in you can call your database connection manually and do queries. I hope this is sufficient.

Answer 4

The $active_group variable lets you choose which connection group to make active. By default there is only one group (the 'default' group).

$active_group = 'default';
$active_record = TRUE;

$db['default']['hostname'] = 'localhost';
$db['default']['username'] = 'root';
$db['default']['password'] = '';
$db['default']['database'] = 'test1';
$db['default']['dbdriver'] = 'mysql'; 
$db['default']['dbprefix'] = '';
$db['default']['pconnect'] = TRUE;
$db['default']['db_debug'] = TRUE;
$db['default']['cache_on'] = FALSE;
$db['default']['cachedir'] = '';
$db['default']['char_set'] = 'utf8';
$db['default']['dbcollat'] = 'utf8_general_ci';
$db['default']['swap_pre'] = '';
$db['default']['autoinit'] = TRUE;
$db['default']['stricton'] = FALSE;

The $active_record variables lets you determine whether or not to load the active record class.

Answer 5

Yes you can connect database at runtime in codeigniter. By default if you donot specify the name of the database it will take the default database

$db['default']['hostname'] = 'localhost';

and if you specify a particular name

$db['db2']['hostname'] = 'localhost';

Like this $this->load->database('db2', TRUE);

I have done same in one of my project , You can create a Table, (if you want dynamic) in which you can store all the database name according to the user login.

So when connecting to the Database in Model , firstly you need to get the database name from the table you create using user login based on that you can do something like this

Here $dbname is the your Database name that we you found by query to default database .

 $admin_db= $this->load->database($dbname, TRUE);
 $q = $admin_db->get('Tablename');

Answer 6

@Pratima as per your comment to Yahia Bat you want to get the details of the database dynamically from some table and then connect to the database. For that you should populate the $config or any other array with the required details from the database and connect accordingly.

$config['hostname'] = '<<value from database table>>';
$config['username'] = '<<value from database table>>';
$config['password'] = '<<value from database table>>';
$config['database'] = '<<value from database table>>';
$config['dbdriver'] = 'mysqli';
$config['dbprefix'] = '';
$config['pconnect'] = FALSE;
$config['db_debug'] = TRUE;
$config['cache_on'] = FALSE;
$config['cachedir'] = '';
$config['char_set'] = 'utf8';
$config['dbcollat'] = 'utf8_general_ci';
$this->load->database($config);

that should solve the issue