php-mysql的封装类

<?php
/**
* Desc: php操作mysql的封装类
* Author zhifeng
* Date: 2015/04/15
* 连接模式：PDO
*/
class MMysql {
protected static $_dbh = null; //静态属性,所有数据库实例共用,避免重复连接数据库
   protected $_dbType = &#39;mysql&#39;;
protected $_pconnect = true; //是否使用长连接
   protected $_host = &#39;localhost&#39;;
protected $_port = 3306;
   protected $_user = &#39;root&#39;;
   protected $_pass = &#39;root&#39;;
   protected $_dbName = null; //数据库名
protected $_sql = false; //最后一条sql语句
   protected $_where = &#39;&#39;;
   protected $_order = &#39;&#39;;
   protected $_limit = &#39;&#39;;
   protected $_field = &#39;*&#39;;
   protected $_clear = 0; //状态，0表示查询条件干净，1表示查询条件污染
   protected $_trans = 0; //事务指令数 
   /**
    * 初始化类
    * @param array $conf 数据库配置
    */
   public function __construct(array $conf) {
class_exists(&#39;PDO&#39;) or die("PDO: class not exists.");
$this->_host = $conf[&#39;host&#39;];
$this->_port = $conf[&#39;port&#39;];
$this->_user = $conf[&#39;user&#39;];
$this->_pass = $conf[&#39;passwd&#39;];
$this->_dbName = $conf[&#39;dbname&#39;];
//连接数据库
       if ( is_null(self::$_dbh) ) {
           $this->_connect();
       }
   }
/**
    * 连接数据库的方法
    */
protected function _connect() {
$dsn = $this->_dbType.&#39;:host=&#39;.$this->_host.&#39;;port=&#39;.$this->_port.&#39;;dbname=&#39;.$this->_dbName;
$options = $this->_pconnect ? array(PDO::ATTR_PERSISTENT=>true) : array();
try { 
$dbh = new PDO($dsn, $this->_user, $this->_pass, $options);
           $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);  //设置如果sql语句执行错误则抛出异常，事务会自动回滚
           $dbh->setAttribute(PDO::ATTR_EMULATE_PREPARES, false); //禁用prepared statements的仿真效果(防SQL注入)
} catch (PDOException $e) { 
           die(&#39;Connection failed: &#39; . $e->getMessage());
}
$dbh->exec(&#39;SET NAMES utf8&#39;);
self::$_dbh = $dbh;
}
   /** 
   * 字段和表名添加 `符号
   * 保证指令中使用关键字不出错 针对mysql 
   * @param string $value 
   * @return string 
   */ 
   protected function _addChar($value) { 
       if (&#39;*&#39;==$value || false!==strpos($value,&#39;(&#39;) || false!==strpos($value,&#39;.&#39;) || false!==strpos($value,&#39;`&#39;)) { 
           //如果包含* 或者 使用了sql方法 则不作处理 
       } elseif (false === strpos($value,&#39;`&#39;) ) { 
           $value = &#39;`&#39;.trim($value).&#39;`&#39;;
       } 
       return $value; 
   }
   /** 
   * 取得数据表的字段信息 
   * @param string $tbName 表名
   * @return array 
   */ 
   protected function _tbFields($tbName) {
       $sql = &#39;SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME="&#39;.$tbName.&#39;" AND TABLE_SCHEMA="&#39;.$this->_dbName.&#39;"&#39;;
       $stmt = self::$_dbh->prepare($sql);
       $stmt->execute();
       $result = $stmt->fetchAll(PDO::FETCH_ASSOC);
       $ret = array();
       foreach ($result as $key=>$value) {
           $ret[$value[&#39;COLUMN_NAME&#39;]] = 1;
       }
       return $ret;
   }
   /** 
   * 过滤并格式化数据表字段
   * @param string $tbName 数据表名 
   * @param array $data POST提交数据 
   * @return array $newdata 
   */
   protected function _dataFormat($tbName,$data) {
       if (!is_array($data)) return array();
       $table_column = $this->_tbFields($tbName);
       $ret=array();
       foreach ($data as $key=>$val) {
           if (!is_scalar($val)) continue; //值不是标量则跳过
           if (array_key_exists($key,$table_column)) {
               $key = $this->_addChar($key);
               if (is_int($val)) { 
                   $val = intval($val); 
               } elseif (is_float($val)) { 
                   $val = floatval($val); 
               } elseif (preg_match(&#39;/^\(\w*(\+|\-|\*|\/)?\w*\)$/i&#39;, $val)) {
                   // 支持在字段的值里面直接使用其它字段 ,例如 (score+1) (name) 必须包含括号
                   $val = $val;
               } elseif (is_string($val)) { 
                   $val = &#39;"&#39;.addslashes($val).&#39;"&#39;;
               }
               $ret[$key] = $val;
           }
       }
       return $ret;
   }
   
   /**
   * 执行查询 主要针对 SELECT, SHOW 等指令
   * @param string $sql sql指令 
   * @return mixed 
   */ 
   protected function _doQuery($sql=&#39;&#39;) {
       $this->_sql = $sql;
       $pdostmt = self::$_dbh->prepare($this->_sql); //prepare或者query 返回一个PDOStatement
       $pdostmt->execute();
       $result = $pdostmt->fetchAll(PDO::FETCH_ASSOC);
       return $result;
   }
   
   /** 
   * 执行语句 针对 INSERT, UPDATE 以及DELETE,exec结果返回受影响的行数
   * @param string $sql sql指令 
   * @return integer 
   */ 
   protected function _doExec($sql=&#39;&#39;) {
       $this->_sql = $sql;
       return self::$_dbh->exec($this->_sql);
   }
   /** 
   * 执行sql语句，自动判断进行查询或者执行操作 
   * @param string $sql SQL指令 
   * @return mixed 
   */ 
   public function doSql($sql=&#39;&#39;) {
       $queryIps = &#39;INSERT|UPDATE|DELETE|REPLACE|CREATE|DROP|LOAD DATA|SELECT .* INTO|COPY|ALTER|GRANT|REVOKE|LOCK|UNLOCK&#39;; 
       if (preg_match(&#39;/^\s*"?(&#39; . $queryIps . &#39;)\s+/i&#39;, $sql)) { 
           return $this->_doExec($sql);
       }
       else {
           //查询操作
           return $this->_doQuery($sql);
       }
   }
   /** 
   * 获取最近一次查询的sql语句 
   * @return String 执行的SQL 
   */ 
   public function getLastSql() { 
       return $this->_sql;
   }
   /**
    * 插入方法
    * @param string $tbName 操作的数据表名
    * @param array $data 字段-值的一维数组
    * @return int 受影响的行数
    */
   public function insert($tbName,array $data){
       $data = $this->_dataFormat($tbName,$data);
       if (!$data) return;
       $sql = "insert into ".$tbName."(".implode(&#39;,&#39;,array_keys($data)).") values(".implode(&#39;,&#39;,array_values($data)).")";
return $this->_doExec($sql);
   }
   /**
    * 删除方法
    * @param string $tbName 操作的数据表名
    * @return int 受影响的行数
    */
   public function delete($tbName) {
       //安全考虑,阻止全表删除
       if (!trim($this->_where)) return false;
       $sql = "delete from ".$tbName." ".$this->_where;
       $this->_clear = 1;
       $this->_clear();
       return $this->_doExec($sql);
   }
   /**
    * 更新函数
    * @param string $tbName 操作的数据表名
    * @param array $data 参数数组
    * @return int 受影响的行数
    */
   public function update($tbName,array $data) {
       //安全考虑,阻止全表更新
       if (!trim($this->_where)) return false;
       $data = $this->_dataFormat($tbName,$data);
       if (!$data) return;
       $valArr = &#39;&#39;;
       foreach($data as $k=>$v){
           $valArr[] = $k.&#39;=&#39;.$v;
       }
       $valStr = implode(&#39;,&#39;, $valArr);
       $sql = "update ".trim($tbName)." set ".trim($valStr)." ".trim($this->_where);
       return $this->_doExec($sql);
   }
   /**
    * 查询函数
    * @param string $tbName 操作的数据表名
    * @return array 结果集
    */
   public function select($tbName=&#39;&#39;) {
       $sql = "select ".trim($this->_field)." from ".$tbName." ".trim($this->_where)." ".trim($this->_order)." ".trim($this->_limit);
       $this->_clear = 1;
       $this->_clear();
       return $this->_doQuery(trim($sql));
   }
   /**
    * @param mixed $option 组合条件的二维数组，例：$option[&#39;field1&#39;] = array(1,&#39;=>&#39;,&#39;or&#39;)
    * @return $this
    */
   public function where($option) {
       if ($this->_clear>0) $this->_clear();
       $this->_where = &#39; where &#39;;
       $logic = &#39;and&#39;;
       if (is_string($option)) {
           $this->_where .= $option;
       }
       elseif (is_array($option)) {
           foreach($option as $k=>$v) {
               if (is_array($v)) {
                   $relative = isset($v[1]) ? $v[1] : &#39;=&#39;;
                   $logic    = isset($v[2]) ? $v[2] : &#39;and&#39;;
                   $condition = &#39; (&#39;.$this->_addChar($k).&#39; &#39;.$relative.&#39; &#39;.$v[0].&#39;) &#39;;
               }
               else {
                   $logic = &#39;and&#39;;
                   $condition = &#39; (&#39;.$this->_addChar($k).&#39;=&#39;.$v.&#39;) &#39;;
               }
               $this->_where .= isset($mark) ? $logic.$condition : $condition;
               $mark = 1;
           }
       }
       return $this;
   }
   /**
    * 设置排序
    * @param mixed $option 排序条件数组 例:array(&#39;sort&#39;=>&#39;desc&#39;)
    * @return $this
    */
   public function order($option) {
       if ($this->_clear>0) $this->_clear();
       $this->_order = &#39; order by &#39;;
       if (is_string($option)) {
           $this->_order .= $option;
       }
       elseif (is_array($option)) {
           foreach($option as $k=>$v){
               $order = $this->_addChar($k).&#39; &#39;.$v;
               $this->_order .= isset($mark) ? &#39;,&#39;.$order : $order;
               $mark = 1;
           }
       }
       return $this;
   }
   /**
    * 设置查询行数及页数
    * @param int $page pageSize不为空时为页数，否则为行数
    * @param int $pageSize 为空则函数设定取出行数，不为空则设定取出行数及页数
    * @return $this
    */
   public function limit($page,$pageSize=null) {
       if ($this->_clear>0) $this->_clear();
       if ($pageSize===null) {
           $this->_limit = "limit ".$page;
       }
       else {
           $pageval = intval( ($page - 1) * $pageSize);
           $this->_limit = "limit ".$pageval.",".$pageSize;
       }
       return $this;
   }
   /**
    * 设置查询字段
    * @param mixed $field 字段数组
    * @return $this
    */
   public function field($field){
       if ($this->_clear>0) $this->_clear();
       if (is_string($field)) {
           $field = explode(&#39;,&#39;, $field);
       }
       $nField = array_map(array($this,&#39;_addChar&#39;), $field);
       $this->_field = implode(&#39;,&#39;, $nField);
       return $this;
   }
   /**
    * 清理标记函数
    */
   protected function _clear() {
       $this->_where = &#39;&#39;;
       $this->_order = &#39;&#39;;
       $this->_limit = &#39;&#39;;
       $this->_field = &#39;*&#39;;
       $this->_clear = 0;
   }
   /**
    * 手动清理标记
    * @return $this
    */
   public function clearKey() {
       $this->_clear();
       return $this;
   }
   /**
   * 启动事务 
   * @return void 
   */ 
   public function startTrans() { 
       //数据rollback 支持 
       if ($this->_trans==0) self::$_dbh->beginTransaction();
       $this->_trans++; 
       return; 
   }
   
   /** 
   * 用于非自动提交状态下面的查询提交 
   * @return boolen 
   */
   public function commit() {
       $result = true;
       if ($this->_trans>0) { 
           $result = self::$_dbh->commit(); 
           $this->_trans = 0;
       } 
       return $result;
   }
   /** 
   * 事务回滚 
   * @return boolen 
   */ 
   public function rollback() {
       $result = true;
       if ($this->_trans>0) {
           $result = self::$_dbh->rollback();
           $this->_trans = 0;
       }
       return $result;
   }
   /**
   * 关闭连接
   * PHP 在脚本结束时会自动关闭连接。
   */
   public function close() {
       if (!is_null(self::$_dbh)) self::$_dbh = null;
   }
}

2. 例子

<?php
$mysql = new MMysql($configArr);
//插入
$data = array(
&#39;sid&#39;=>101,
&#39;aa&#39;=>123456,
&#39;bbc&#39;=>&#39;aaaaaaaaaaaaaa&#39;,
);
$mysql->insert(&#39;t_table&#39;,$data);
//查询
$res = $mysql->field(array(&#39;sid&#39;,&#39;aa&#39;,&#39;bbc&#39;))
->order(array(&#39;sid&#39;=>&#39;desc&#39;,&#39;aa&#39;=>&#39;asc&#39;))
->where(array(&#39;sid&#39;=>"101",&#39;aa&#39;=>array(&#39;123455&#39;,&#39;>&#39;,&#39;or&#39;)))
->limit(1,2)
->select(&#39;t_table&#39;);
$res = $mysql->field(&#39;sid,aa,bbc&#39;)
->order(&#39;sid desc,aa asc&#39;)
->where(&#39;sid=101 or aa>123455&#39;)
->limit(1,2)
->select(&#39;t_table&#39;);
//获取最后执行的sql语句
$sql = $mysql->getLastSql();
//直接执行sql语句
$sql = "show tables";
$res = $mysql->doSql($sql);
//事务
$mysql->startTrans();
$mysql->where(array(&#39;sid&#39;=>102))->update(&#39;t_table&#39;,array(&#39;aa&#39;=>666666));
$mysql->where(array(&#39;sid&#39;=>103))->update(&#39;t_table&#39;,array(&#39;bbc&#39;=>&#39;呵呵8888呵呵&#39;));
$mysql->where(array(&#39;sid&#39;=>104))->delete(&#39;t_table&#39;);
$mysql->commit();