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 = 'mysql';
protected $_pconnect = true; //是否使用长连接
   protected $_host = 'localhost';
protected $_port = 3306;
   protected $_user = 'root';
   protected $_pass = 'root';
   protected $_dbName = null; //数据库名
protected $_sql = false; //最后一条sql语句
   protected $_where = '';
   protected $_order = '';
   protected $_limit = '';
   protected $_field = '*';
   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('PDO') or die("PDO: class not exists.");
$this->_host = $conf['host'];
$this->_port = $conf['port'];
$this->_user = $conf['user'];
$this->_pass = $conf['passwd'];
$this->_dbName = $conf['dbname'];
//连接数据库
       if ( is_null(self::$_dbh) ) {
           $this->_connect();
       }
   }
/**
    * 连接数据库的方法
    */
protected function _connect() {
$dsn = $this->_dbType.':host='.$this->_host.';port='.$this->_port.';dbname='.$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('Connection failed: ' . $e->getMessage());
}
$dbh->exec('SET NAMES utf8');
self::$_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 ('*'==$value || false!==strpos($value,'(') || false!==strpos($value,'.') || false!==strpos($value,'`')) { 
           //如果包含* 或者 使用了sql方法 则不作处理 
       } elseif (false === strpos($value,'`') ) { 
           $value = '`'.trim($value).'`';
       } 
       return $value; 
   }
   /** 
   * 取得数据表的字段信息 
   * @param string $tbName 表名
   * @return array 
   */ 
   protected function _tbFields($tbName) {
       $sql = 'SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME="'.$tbName.'" AND TABLE_SCHEMA="'.$this->_dbName.'"';
       $stmt = self::$_dbh->prepare($sql);
       $stmt->execute();
       $result = $stmt->fetchAll(PDO::FETCH_ASSOC);
       $ret = array();
       foreach ($result as $key=>$value) {
           $ret[$value['COLUMN_NAME']] = 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('/^\(\w*(\+|\-|\*|\/)?\w*\)$/i', $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)) { 
                   $val = '"'.addslashes($val).'"';
               }
               $ret[$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='') {
       $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='') {
       $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='') {
       $queryIps = 'INSERT|UPDATE|DELETE|REPLACE|CREATE|DROP|LOAD DATA|SELECT .* INTO|COPY|ALTER|GRANT|REVOKE|LOCK|UNLOCK'; 
       if (preg_match('/^\s*"?(' . $queryIps . ')\s+/i', $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(',',array_keys($data)).") values(".implode(',',array_values($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;
       $valArr = '';
       foreach($data as $k=>$v){
           $valArr[] = $k.'='.$v;
       }
       $valStr = implode(',', $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='') {
       $sql = "select ".trim($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['field1'] = array(1,'=>','or')
    * @return $this
    */
   public function where($option) {
       if ($this->_clear>0) $this->_clear();
       $this->_where = ' where ';
       $logic = 'and';
       if (is_string($option)) {
           $this->_where .= $option;
       }
       elseif (is_array($option)) {
           foreach($option as $k=>$v) {
               if (is_array($v)) {
                   $relative = isset($v[1]) ? $v[1] : '=';
                   $logic    = isset($v[2]) ? $v[2] : 'and';
                   $condition = ' ('.$this->_addChar($k).' '.$relative.' '.$v[0].') ';
               }
               else {
                   $logic = 'and';
                   $condition = ' ('.$this->_addChar($k).'='.$v.') ';
               }
               $this->_where .= isset($mark) ? $logic.$condition : $condition;
               $mark = 1;
           }
       }
       return $this;
   }
   /**
    * 设置排序
    * @param mixed $option 排序条件数组 例:array('sort'=>'desc')
    * @return $this
    */
   public function order($option) {
       if ($this->_clear>0) $this->_clear();
       $this->_order = ' order by ';
       if (is_string($option)) {
           $this->_order .= $option;
       }
       elseif (is_array($option)) {
           foreach($option as $k=>$v){
               $order = $this->_addChar($k).' '.$v;
               $this->_order .= isset($mark) ? ','.$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(',', $field);
       }
       $nField = array_map(array($this,'_addChar'), $field);
       $this->_field = implode(',', $nField);
       return $this;
   }
   /**
    * 清理标记函数
    */
   protected function _clear() {
       $this->_where = '';
       $this->_order = '';
       $this->_limit = '';
       $this->_field = '*';
       $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(
'sid'=>101,
'aa'=>123456,
'bbc'=>'aaaaaaaaaaaaaa',
);
$mysql->insert('t_table',$data);
//查询
$res = $mysql->field(array('sid','aa','bbc'))
->order(array('sid'=>'desc','aa'=>'asc'))
->where(array('sid'=>"101",'aa'=>array('123455','>','or')))
->limit(1,2)
->select('t_table');
$res = $mysql->field('sid,aa,bbc')
->order('sid desc,aa asc')
->where('sid=101 or aa>123455')
->limit(1,2)
->select('t_table');
//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('sid'=>102))->update('t_table',array('aa'=>666666));
$mysql->where(array('sid'=>103))->update('t_table',array('bbc'=>'呵呵8888呵呵'));
$mysql->where(array('sid'=>104))->delete('t_table');
$mysql->commit();