codeigniter - 使用 codeigniter 实现读取副本

Question

我正在使用 codigniter 框架开发 PHP 应用程序。并使用亚马逊只读副本设置。我需要一种方法来处理通过只读数据库的所有选择查询和通过主数据库处理所有更新相关的查询。以下是我在脚本中使用的当前用法。

数据库配置文件

$db['default']['hostname'] = 'master_db_host';
$db['default']['username'] = 'dbuser';
$db['default']['password'] = 'dbpassword';
$db['default']['database'] = 'db_name';
$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;

模型脚本

class replica_model extends CI_Model {

    function __construct()
    {
        parent::__construct();
    }

    public function write($data)
    {
        $this->db->insert('dumy', $data);
        return $this->db->insert_id();
    }

    public function read()
    {
        $query = $this->db->get("dumy");
        return $query->result();
    }

}

有人可以帮我修改脚本以基于读写访问主副本吗？

Answer 1

我们可以使用 codeigniter 处理多个数据库。首先我们可以看看配置文件需要如何设置。

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

//Master DB config values
$db['default']['hostname'] = 'master_db_host';
$db['default']['username'] = 'db_user';
$db['default']['password'] = 'db_pass';
$db['default']['database'] = 'db_name';
$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;


//Replica DB config values
$db['read_replica']['hostname'] = 'replica_db_host';
$db['read_replica']['username'] = 'db_user';
$db['read_replica']['password'] = 'db_password';
$db['read_replica']['database'] = 'db_name';
$db['read_replica']['dbdriver'] = 'mysql';
$db['read_replica']['dbprefix'] = '';
$db['read_replica']['pconnect'] = FALSE;
$db['read_replica']['db_debug'] = TRUE;
$db['read_replica']['cache_on'] = FALSE;
$db['read_replica']['cachedir'] = '';
$db['read_replica']['char_set'] = 'utf8';
$db['read_replica']['dbcollat'] = 'utf8_general_ci';
$db['read_replica']['swap_pre'] = '';
$db['read_replica']['autoinit'] = TRUE;
$db['read_replica']['stricton'] = FALSE;

参数“$db['read_replica']['pconnect']”在主数据库配置上应为 true，在副本配置上应为 false。否则，当我们启用副本数据库时，主数据库配置也会被副本配置覆盖。

然后模型的使用将如下所示。

class Replica_model extends CI_Model {

    function __construct()
    {
        parent::__construct();
        $this->db_replica = $this->load->database('read_replica',TRUE);
    }

    public function write($data)
    {
        $this->db->insert('dumy', $data);
        return $this->db->insert_id();
    }

    public function read()
    {
        $query = $this->db_replica->get("dumy");
        return $query->result();
    }

}