Codeigniter - 多个数据库连接

Question

我必须从master数据库中检索MySQL数据库信息，然后连接到该数据库，并获取一些记录。

我的意思是拿着一个我要加载另一个数据库的数据库。

Codeigniter可以吗？现在我在我的模型中使用以下代码行。

function connectDb($credential)
{

    $config['hostname'] = $credential['server'];
    $config['username'] = $credential['username'];
    $config['password'] = $credential['password'];
    $config['database'] = $credential['database'];
    $config['dbdriver'] = "mysql";
    $config['dbprefix'] = "";
    $config['pconnect'] = FALSE;
    $config['db_debug'] = TRUE;
    $config['cache_on'] = FALSE;
    $config['cachedir'] = "";
    $config['char_set'] = "utf8";
    $config['dbcollat'] = "utf8_general_ci";

    $DB2=$this->load->database($config);

    $DB2->db->select('first_name,last_name');
    $query = $DB2->db->get('person');
    print_r($query);

}

它没有其他工作方式吗？

Answer 1

您应该在`application / config / database.php'

中提供第二个数据库信息

通常，您可以设置default数据库组，如下所示：

$db['default']['hostname'] = "localhost";
$db['default']['username'] = "root";
$db['default']['password'] = "";
$db['default']['database'] = "database_name";
$db['default']['dbdriver'] = "mysql";
$db['default']['dbprefix'] = "";
$db['default']['pconnect'] = TRUE;
$db['default']['db_debug'] = FALSE;
$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;

请注意，登录信息和设置在名为$db['default']的数组中提供。

然后，您可以在新数组中添加另一个数据库 - 让我们称之为'otherdb'。

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

现在，要实际使用第二个数据库，您必须将连接发送到您可以在模型中使用的另一个变量：

function my_model_method()
{
  $otherdb = $this->load->database('otherdb', TRUE); // the TRUE paramater tells CI that you'd like to return the database object.

  $query = $otherdb->select('first_name, last_name')->get('person');
  var_dump($query);
}

应该这样做。 可以在此处找到连接到多个数据库的文档：http://codeigniter.com/user_guide/database/connecting.html

Answer 2

最好的方法是使用不同的数据库组。如果您想像往常一样继续使用master数据库（$ this-＆gt; db），只需关闭 persistent connexion 配置选项到您的辅助数据库。只有master数据库才能使用持久连接：

主数据库

$db['default']['hostname'] = "localhost";
$db['default']['username'] = "root";
$db['default']['password'] = "";
$db['default']['database'] = "database_name";
$db['default']['dbdriver'] = "mysql";
$db['default']['dbprefix'] = "";
$db['default']['pconnect'] = TRUE;
$db['default']['db_debug'] = FALSE;
$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;

辅助数据库（通知pconnect设置为false）

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

然后您可以像往常一样使用主数据库时将辅助数据库用作数据库对象：

// use master dataabse
$users = $this->db->get('users');

// connect to secondary database
$otherdb = $this->load->database('otherdb', TRUE);
$stuff = $otherdb->get('struff');
$otherdb->insert_batch('users', $users->result_array());

// keep using master database as usual, for example insert stuff from other database
$this->db->insert_batch('stuff', $stuff->result_array());

Answer 3

使用此功能。

$dsn1 = 'mysql://user:password@localhost/db1';
$this->db1 = $this->load->database($dsn1, true);     

$dsn2 = 'mysql://user:password@localhost/db2';
$this->db2= $this->load->database($dsn2, true);     

$dsn3 = 'mysql://user:password@localhost/db3';
$this->db3= $this->load->database($dsn3, true);   

用法

$this->db1 ->insert('tablename', $insert_array);
$this->db2->insert('tablename', $insert_array);
$this->db3->insert('tablename', $insert_array);

Answer 4

在查看代码时，我唯一看错的是，当您尝试加载第二个数据库时：

$DB2=$this->load->database($config);

如果要检索数据库对象，则必须在第二个参数中传递 TRUE 。

来自Codeigniter User Guide：

  

通过将第二个参数设置为TRUE（布尔值），函数将会   返回数据库对象。

因此，您的代码应该是：

$DB2=$this->load->database($config, TRUE);

这将使其发挥作用。

Answer 5

This is default database :

$db['default'] = array(
    'dsn'   => '',
    'hostname' => 'localhost',
    'username' => 'root',
    'password' => '',
    'database' => 'mydatabase',
    'dbdriver' => 'mysqli',
    'dbprefix' => '',
    'pconnect' => TRUE,
    'db_debug' => (ENVIRONMENT !== 'production'),
    'cache_on' => FALSE,
    'cachedir' => '',
    'char_set' => 'utf8',
    'dbcollat' => 'utf8_general_ci',
    'swap_pre' => '',
    'encrypt' => FALSE,
    'compress' => FALSE,
    'stricton' => FALSE,
    'failover' => array(),
    'save_queries' => TRUE
);

Add another database at the bottom of database.php file
$db['second'] = array(
    'dsn'   => '',
    'hostname' => 'localhost',
    'username' => 'root',
    'password' => '',
    'database' => 'mysecond',
    'dbdriver' => 'mysqli',
    'dbprefix' => '',
    'pconnect' => TRUE,
    'db_debug' => (ENVIRONMENT !== 'production'),
    'cache_on' => FALSE,
    'cachedir' => '',
    'char_set' => 'utf8',
    'dbcollat' => 'utf8_general_ci',
    'swap_pre' => '',
    'encrypt' => FALSE,
    'compress' => FALSE,
    'stricton' => FALSE,
    'failover' => array(),
    'save_queries' => TRUE
);

In autoload.php config file
$autoload['libraries'] = array('database', 'email', 'session');


The default database is worked fine by autoload the database library but second database load and connect by using constructor in model and controller...
<?php
    class Seconddb_model extends CI_Model {
        function __construct(){
            parent::__construct();
            //load our second db and put in $db2
            $this->db2 = $this->load->database('second', TRUE);
        }

        public function getsecondUsers(){
            $query = $this->db2->get('members');
            return $query->result(); 
        }

    }
?>

Answer 6

default database
$db['default'] = array(
    'dsn'   => '',
    'hostname' => 'localhost',
    'username' => 'root',
    'password' => '',
    'database' => 'test',
    'dbdriver' => 'mysqli',
    'dbprefix' => '',
    'pconnect' => FALSE,
    'db_debug' => (ENVIRONMENT !== 'production'),
    'cache_on' => FALSE,
    'cachedir' => '',
    'char_set' => 'utf8',
    'dbcollat' => 'utf8_general_ci',
    'swap_pre' => '',
    'encrypt' => FALSE,
    'compress' => FALSE,
    'stricton' => FALSE,
    'failover' => array(),
    'save_queries' => TRUE
);
another db
$db['database2'] = array(
    'dsn' => '',
    'hostname' => 'localhost',
    'username' => 'root',
    'password' => '',
    'database' => 'test_2', // Database name
    'dbdriver' => 'mysqli',
    'dbprefix' => '',
    'pconnect' => FALSE,
    'db_debug' => (ENVIRONMENT !== 'production'),
    'cache_on' => FALSE,
    'cachedir' => '',
    'char_set' => 'utf8',
    'dbcollat' => 'utf8_general_ci',
    'swap_pre' => '',
    'encrypt' => FALSE,
    'compress' => FALSE,
    'stricton' => FALSE,
    'failover' => array(),
    'save_queries' => TRUE
   );

在你必须调用的模型中

public function getRecords(){
    // Load database
    $db2 = $this->load->database('database2', TRUE);  

   // Select records from 1st database
   $this->db->select('*');
   $query = $this->db->get('record1');
   $result1 = $query->result_array();  

// Select records from 2nd database
   $db2->select('*');
   $query = $db2->get('record2');
   $result2 = $query->result_array();
   $response = array("response1"=>$result1,"response2"=>$result2);
   return $response;
 }

Answer 7

If you need to connect to more than one database simultaneously you can do so as follows:

$DB1 = $this->load->database('group_one', TRUE);
$DB2 = $this->load->database('group_two', TRUE);

注意：将单词“ group_one”和“ group_two”更改为您要连接的特定组名（或者您可以按照上面的说明传递连接值）。

通过将第二个参数设置为TRUE（布尔值），该函数将返回数据库对象。

访问https://www.codeigniter.com/userguide3/database/connecting.html以获取更多信息。