Yii中实现主从数据库配置方法

来源：互联网发布：慢走丝编程基本教程编辑：程序博客网时间：2024/05/29 05:01

现在Yii框架没有配置主从数据库，本人对yii增加的扩展（不修改原现的框架为基础），得写了数据库连接的方式，实现了一主多从，同时也可以连接多个不同的数据库（支持一主多从）.详细代码如下：

一、介绍一主多从的配置：

1.extensions目录下增加DbConnectionMan.php文件，代码如下：

<?php/** * 主数据库 写 从数据库（可多个）读 * 实现主从数据库 读写分离 主服务器无法连接 从服务器可切换写功能 * 从务器无法连接 主服务器可切换读功 * @author: pzliang QQ：327168521 * Date:2013-10-21 * */class DbConnectionMan extends CDbConnection {    public $timeout = 10; //连接超时时间    public $markDeadSeconds = 600; //如果从数据库连接失败 600秒内不再连接    //用 cache 作为缓存全局标记    public $cacheID = 'cache';    /**     * @var array $slaves.Slave database connection(Read) config array.     * 配置符合 CDbConnection.     * @example     * 'components'=>array(     * 'db'=>array(     * 'connectionString'=>'mysql://<master>',     * 'slaves'=>array(     * array('connectionString'=>'mysql://<slave01>'),     * array('connectionString'=>'mysql://<slave02>'),     * )     * )     * )     * */    public $slaves = array();    /**     *     * 从数据库状态 false 则只用主数据库     * @var bool $enableSlave     * */    public $enableSlave = true;    /**     * @var slavesWrite 紧急情况主数据库无法连接 切换从服务器（读写）.     */    public $slavesWrite = false;    /**     * @var masterRead 紧急情况从主数据库无法连接 切换从住服务器（读写）.     */    public $masterRead = false;    /**     * @var _slave     */    private $_slave;    /**     * @var _disableWrite 从服务器（只读）.     */    private $_disableWrite = true;    /**     *     * 重写 createCommand 方法,1.开启从库 2.存在从库 3.当前不处于一个事务中 4.从库读数据     * @param string $sql     * @return CDbCommand     * */    public function createCommand($sql = null) {        if ($this->enableSlave && !empty($this->slaves) && is_string($sql) && !$this->getCurrentTransaction() && self::isReadOperation($sql) && ($slave = $this->getSlave())        ) {            return $slave->createCommand($sql);        } else {            if (!$this->masterRead) {                if ($this->_disableWrite && !self::isReadOperation($sql)) {                    throw new CDbException("Master db server is not available now!Disallow write operation on slave server!");                }            }            return parent::createCommand($sql);        }    }    /**     * 获得从服务器连接资源     * @return CDbConnection     * */    public function getSlave() {        if (!isset($this->_slave)) {            shuffle($this->slaves);            foreach ($this->slaves as $slaveConfig) {                if ($this->_isDeadServer($slaveConfig['connectionString'])) {                    continue;                }                if (!isset($slaveConfig['class']))                    $slaveConfig['class'] = 'CDbConnection';                $slaveConfig['autoConnect'] = false;                try {                    if ($slave = Yii::createComponent($slaveConfig)) {                        Yii::app()->setComponent('dbslave', $slave);                        $slave->setAttribute(PDO::ATTR_TIMEOUT, $this->timeout);                        $slave->setAttribute(PDO::MYSQL_ATTR_USE_BUFFERED_QUERY, true);                        $slave->setActive(true);                        $this->_slave = $slave;                        break;                    }                } catch (Exception $e) {                    $this->_markDeadServer($slaveConfig['connectionString']);                    Yii::log("Slave database connection failed!\n\tConnection string:{$slaveConfig['connectionString']}", 'warning');                    continue;                }            }            if (!isset($this->_slave)) {                $this->_slave = null;                $this->enableSlave = false;            }        }        return $this->_slave;    }    public function setActive($value) {        if ($value != $this->getActive()) {            if ($value) {                try {                    if ($this->_isDeadServer($this->connectionString)) {                        throw new CDbException('Master db server is already dead!');                    }                    //PDO::ATTR_TIMEOUT must set before pdo instance create                    $this->setAttribute(PDO::ATTR_TIMEOUT, $this->timeout);                    $this->open();                } catch (Exception $e) {                    $this->_markDeadServer($this->connectionString);                    $slave = $this->getSlave();                    Yii::log($e->getMessage(), CLogger::LEVEL_ERROR, 'exception.CDbException');                    if ($slave) {                        $this->connectionString = $slave->connectionString;                        $this->username = $slave->username;                        $this->password = $slave->password;                        if ($this->slavesWrite) {                            $this->_disableWrite = false;                        }                        $this->open();                    } else { //Slave also unavailable                        if ($this->masterRead) {                            $this->connectionString = $this->connectionString;                            $this->username = $this->username;                            $this->password = $this->password;                            $this->open();                        } else {                            throw new CDbException(Yii::t('yii', 'CDbConnection failed to open the DB connection.'), (int) $e->getCode(), $e->errorInfo);                        }                    }                }            } else {                $this->close();            }        }    }    /**     * 检测读操作 sql 语句     *     * 关键字： SELECT,DECRIBE,SHOW ...     * 写操作:UPDATE,INSERT,DELETE ...     * */    public static function isReadOperation($sql) {        $sql = substr(ltrim($sql), 0, 10);        $sql = str_ireplace(array('SELECT', 'SHOW', 'DESCRIBE', 'PRAGMA'), '^O^', $sql); //^O^,magic smile        return strpos($sql, '^O^') === 0;    }    /**     * 检测从服务器是否被标记 失败.     */    private function _isDeadServer($c) {        $cache = Yii::app()->{$this->cacheID};        if ($cache && $cache->get('DeadServer::' . $c) == 1) {            return true;        }        return false;    }    /**     * 标记失败的slaves.     */    private function _markDeadServer($c) {        $cache = Yii::app()->{$this->cacheID};        if ($cache) {            $cache->set('DeadServer::' . $c, 1, $this->markDeadSeconds);        }    }}

2.config/main.php加增加以下代码

//------------------------主从数据库配置开始------------------------------------'db2'=>array('class'=>'application.extensions.DbConnectionMan',//扩展路径'connectionString' => 'mysql:host=127.0.0.1;dbname=esk_eboss_db',//主数据库 写'emulatePrepare' => true,'username' => 'root','password' => 'root','charset' => 'utf8','tablePrefix' => 'eboss_', //表前缀'enableSlave'=>true,//从数据库启用'slavesWrite'=>false,//紧急情况 主数据库无法连接 启用从数据库 写功能'masterRead'=>true,//紧急情况 从数据库无法连接 启用主数据库 读功能'enableProfiling'=>true,'slaves'=>array(//从数据库 读array(//slave1                        'connectionString'=>'mysql:host=localhost;dbname=test',                        'emulatePrepare' => true,                        'username'=>'root',                        'password'=>'root',                        'charset' => 'utf8',                        'enableProfiling'=>true,                        //'tablePrefix' => 'xcpt_', //表前缀),array(//slave2                        'connectionString'=>'mysql:host=localhost;dbname=yg_eboss_db',                        'emulatePrepare' => true,                        'username'=>'root',                        'password'=>'root',                        'charset' => 'utf8',                        'enableProfiling'=>true,                        //'tablePrefix' => 'xcpt_', //表前缀),),),

以上是配置一主多从的配置，欢迎指正！

二、配置同时连接多个不同的数据库（支持一主多从的方式）：

1.components目录下创建ActiveRecord.php文件代码如下：

<?phpclass ActiveRecord extends CActiveRecord{    public function getDbConnection() {        if(self::$db!==null) {            return self::$db;        } else {                                      self::$db=Yii::app()->getComponent('db2');//这里是我们要修改的 db2就是另一个数据库             //self::$db=Yii::app()->db1;            if(self::$db instanceof CDbConnection)                return self::$db;            else            throw new CDbException(Yii::t('yii','Active Record requires a "db2" CDbConnection application component.'));        }    }}

2.配置连接db2配置把上面config.php中的 db的配置复制一份同时把db 修改成db2就可以了！

3.在model创建 Category.php（只是示例，模型名称大家可以随意定的哦）代码如下：

<?php/* * * @类别表模型 eboss_cate * @author pzliang QQ:327168521 * @CreateDate 2014-02-18 */class Category extends ActiveRecord  //一下要继承components目录下的ActiveRecord.php这个文件中的类哦{public static function model($className = __CLASS__){return parent::model($className);}public function tableName(){return "{{cate}}";}public function rules(){return array(array('cat_name,root_id,ts','required'));}}

4.控制器中的调用方式是：

$info = Category::model()->find();

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