Codeigniter - 多数据库连接

Question

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

我的意思是持有一个数据库我想加载另一个数据库。

Codeigniter 可以吗？ 现在我在我的 model 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);

}

它不工作还有其他方法吗？

Answer 1

您应该在“application/config/database.php”中提供第二个数据库信息

通常，您会设置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 - 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);
}

那应该这样做。 连接多个数据库的文档可以在这里找到： 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主数据库（$this->db），只需关闭辅助数据库的持久连接配置选项。 只有主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（注意 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辅助数据库作为数据库对象，同时使用主数据库：

// 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

用这个。

$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

它对我来说很好（Codeigniter 3）......

这是默认数据库：

$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
);

在 database.php 文件的底部添加另一个数据库

$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
);

在 autoload.php 配置文件中

$autoload['libraries'] = array('database', 'email', 'session');

默认数据库通过自动加载数据库库可以正常工作，但第二个数据库通过使用模型和控制器中的构造函数加载和连接......

<?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 5

在查看您的代码时，我唯一看到错误的是当您尝试加载第二个数据库时：

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

当您想要检索数据库对象时，您必须在第二个参数中传递TRUE 。

来自Codeigniter 用户指南：

通过将第二个参数设置为 TRUE（布尔值），函数将返回数据库对象。

因此，您的代码应该是：

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

这将使它工作。

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
   );

在模型中你必须调用

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”更改为您要连接到的特定组名称（或者您可以传递上述连接值）。

通过将第二个参数设置为 TRUE（布尔值），函数将返回数据库对象。

访问https://www.codeigniter.com/userguide3/database/connecting.html了解更多信息。

Answer 8

作为其他答案的补充，如果要更改 model 本身内的活动数据库组，因此不需要使用另一个数据库连接，请在 model ZA2F2ED4F8EBC2CBB4C21A29DC40AB61D 中使用以下内容：

public function set_database($database)
{
    $CI =& get_instance();
    $CI->db = null;
    $this->load->database($database);
}

从 controller 调用后，如：

$this->my_model->set_database('other_db');

然后，您可以使用其他 model 方法作用于新指定的数据库组，例如：

$this->my_model->insert($data);

注意：目前，仅使用 codeigniter 3 进行测试。