php封装pdo操作数据的工具类

<?php
header("Content-Type:text/html;charset=utf-8");

class PdoMysql{
	public static $config = array();//设置连接参数，配置信息
	public static $link = null;//保存连接标识符
	public static $pconnect = false;//是否开启长连接
	public static $dbVersion = null;//保存数据库版本
	public static $connected = false;//判断是否连接成功
	public static $PDOStatement = null;//保证PDOStatement对象
	public static $queryStr = null;//保存最后执行的操作
	public static $error = null;//保存错误信息
	public static $lastInsertId = null;//保存上一步插入操作保存的AUTO_INCREMANT
	public static $numRows = null;//受影响记录的条数

	/**
	 * 构造函数，连接数据库
	 *
	 * @param      array|string  $dbConfig  The database configuration
	 *
	 * @return     boolean       ( description_of_the_return_value )
	 */
	public function __construct($dbConfig=''){
		if(!class_exists("PDO")){
			self::throw_exception("不支持PDO,请先开启");
		}
		if(!is_array($dbConfig)){
			$dbConfig = array(
							'hostname' => 'localhost',
							'username' => 'root',
							'password' => '1234',
							'database' => 'test',
							'hostport' => '3306',
							'dbms' 	   => 'mysql',
							'dsn'	   => 'mysql:host=localhost;dbname=test'
						);
		}
		if(empty($dbConfig['hostname'])){
			self::throw_exception("没有定义数据库配置,请先定义");
		}

		self::$config = $dbConfig;

		if(empty(self::$config['params'])){
			self::$config['params'] = array();
		}

		if(!isset(self::$link)){
			$configs = self::$config;
			if(self::$pconnect){
				//开启长连接,添加到配置数组中
				$configs['params'][constant("PDO::ATTR_PERSISTENT")] = true;
			}

			try {
				self::$link = new PDO($configs['dsn'],$configs['username'],$configs['password'],$configs['params']);
			} catch (PDOException $e) {
				self::throw_exception($e->getMessage());
			}

			if(!self::$link){
				self::throw_exception("PDO连接错误");
				return false;
			}
			self::$link->exec("set names utf8");
			self::$dbVersion = self::$link->getAttribute(constant("PDO::ATTR_SERVER_VERSION"));
			unset($configs);
		}
	}

	/**
	 * 得到所有记录
	 *
	 * @param      <type>  $sql    The sql
	 *
	 * @return     <type>  All.
	 */
	public static function getAll($sql=null){
		if($sql!=null){
			self::query($sql);
		}
		$result = self::$PDOStatement->fetchAll(constant("PDO::FETCH_ASSOC"));
		return $result;
	}

	/**
	 * 得到一条记录
	 *
	 * @param      <type>  $sql    The sql
	 *
	 * @return     <type>  The row.
	 */
	public static function getRow($sql=null){
		if($sql!=null){
			self::query($sql);
		}
		$result = self::$PDOStatement->fetch(constant("PDO::FETCH_ASSOC"));
		return $result;
	}

	/**
	 * 执行增删改操作，返回受影响记录的条数
	 *
	 * @param      <type>   $sql    The sql
	 *
	 * @return     boolean  ( description_of_the_return_value )
	 */
	public static function execute($sql=null){
		$link = self::$link;
		if(!$link)return false;
		if($sql!=null){
			self::$queryStr = $sql;
		}
		if(!empty(self::$PDOStatement))self::free();
		$result = $link->exec(self::$queryStr);
		self::haveErrorThrowException();
		if($result){
			self::$lastInsertId = $link->lastInsertId();
			self::$numRows = $result;
			return $result;
		}else{
			return false;
		}
	}

	/**
	 * 根据主键查找记录
	 *
	 * @param      <type>  $tabName  The tab name
	 * @param      <type>  $priId    The pri identifier
	 * @param      string  $fields   The fields
	 *
	 * @return     <type>  ( description_of_the_return_value )
	 */
	public static function findById($tabName,$priId,$fields='*'){
		$sql = 'SELECT %s FROM %s WHERE id=%d';
		return self::getRow(sprintf($sql,self::parseFields($fields),$tabName,$priId));
	}

	/**
	 * 执行普通查询
	 *
	 * @param      <type>  $tables  The tables
	 * @param      <type>  $where   The where
	 * @param      string  $fields  The fields
	 * @param      <type>  $group   The group
	 * @param      <type>  $having  The having
	 * @param      <type>  $order   The order
	 * @param      <type>  $limit   The limit
	 *
	 * @return     <type>  ( description_of_the_return_value )
	 */
	public static function find($tables,$where=null,$fields='*',$group=null,$having=null,$order=null,$limit
		=null){
		$sql = 'SELECT '.self::parseFields($fields).' FROM '.$tables
		.self::parseWhere($where)
		.self::parseGroup($group)
		.self::parseHaving($having)
		.self::parseOrder($order)
		.self::parseLimit($limit);
		$data = self::getAll($sql);
		return $data;
	}

	/**
	 * 添加记录
	 *
	 * @param      <type>  $data   The data
	 * @param      <type>  $table  The table
	 *
	 * @return     <type>  ( description_of_the_return_value )
	 */
	public static function add($data,$table){
		$keys = array_keys($data);
		array_walk($keys, array('PdoMySQL','addSpecialChar'));
		$fieldsStr = join(',',$keys);
		$values = "'".join("','",array_values($data))."'";
		$sql = "INSERT {$table}({$fieldsStr}) VALUES({$values})";
		return self::execute($sql);
	}

	/**
	 * 更新数据
	 *
	 * @param      <type>  $data   The data
	 * @param      <type>  $table  The table
	 * @param      <type>  $where  The where
	 * @param      <type>  $order  The order
	 * @param      <type>  $limit  The limit
	 */
	public static function update($data,$table,$where=null,$order=null,$limit=null){
		$sets = '';
		foreach ($data as $key => $value) {
			$sets .= $key."='".$value."',";
		}
		$sets = rtrim($sets,',');
		$sql = "UPDATE {$table} SET {$sets}".self::parseWhere($where).self::parseOrder($order).self::parseLimit($limit);
		echo $sql;
	}

	/**
	 * 删除数据
	 *
	 * @param      <type>  $data   The data
	 * @param      <type>  $table  The table
	 * @param      <type>  $where  The where
	 * @param      <type>  $order  The order
	 * @param      <type>  $limit  The limit
	 *
	 * @return     <type>  ( description_of_the_return_value )
	 */
	public static function delete($table,$where=null,$order=null,$limit=null){
		$sql = "DELETE FROM {$table} ".self::parseWhere($where).self::parseOrder($order).self::parseLimit($limit);
		return self::execute($sql);
	}

	
	/**
	 * 执行查询
	 *
	 * @param      string   $sql    The sql
	 *
	 * @return     boolean  ( description_of_the_return_value )
	 */
	public static function query($sql=''){
		$link = self::$link;
		if(!$link)return false;

		//判断之前是否有结果集，如果有的话，释放结果集
		if(!empty(self::$PDOStatement))self::free();
		self::$queryStr = $sql;
		self::$PDOStatement = $link->prepare(self::$queryStr);
		$res = self::$PDOStatement->execute();
		self::haveErrorThrowException();
		return $res;
	}

	/**
	 * 获取最后执行的sql
	 *
	 * @return     boolean  The last sql.
	 */
	public static function getLastSql(){
		$link = self::$link;
		if(!$link){
			return false;
		}
		return self::$queryStr;
	}

	/**
	 * 获取最后插入的ID
	 *
	 * @return     boolean  The last insert identifier.
	 */
	public static function getLastInsertId(){
		$link = self::$link;
		if(!$link){
			return false;
		}
		return self::$lastInsertId;
	}

	/**
	 * 获得数据库的版本
	 *
	 * @return     boolean  The database version.
	 */
	public static function getDbVersion(){
		$link = self::$link;
		if(!$link){
			return false;
		}
		return self::$dbVersion;
	}

	/**
	 * 得到数据库中表
	 *
	 * @return     array  ( description_of_the_return_value )
	 */
	public static function showTables(){
		$tables = array();
		if(self::query("show tables")){
			$result = self::getAll();
			foreach ($result as $key => $value) {
				$tables[$key] = current($value);
			}
		}
		return $tables;
	}

	/**
	 * 解析where条件
	 *
	 * @param      <type>  $where  The where
	 *
	 * @return     <type>  ( description_of_the_return_value )
	 */
	public static function parseWhere($where){
		$whereStr = '';
		if(is_string($where)&&!empty($where)){
			$whereStr = $where;
		}
		return empty($whereStr) ? '' : ' WHERE '.$whereStr;
	}

	/**
	 * 解析group
	 *
	 * @param      <type>  $group  The group
	 *
	 * @return     <type>  ( description_of_the_return_value )
	 */
	public static function parseGroup($group){
		$groupStr = '';
		if(is_array($group)){
			$groupStr = implode(',', $group);
		}elseif(is_string($group)&&!empty($group)){
			$groupStr = $group;
		}
		return empty($groupStr) ? '' : ' GROUP BY '.$groupStr;
	}

	/**
	 * 解析having
	 *
	 * @param      <type>  $having  The having
	 *
	 * @return     <type>  ( description_of_the_return_value )
	 */
	public static function parseHaving($having){
		$havingStr = '';
		if(is_string($having)&&!empty($having)){
			$havingStr = $having;
		}
		return empty($havingStr) ? '' : ' HAVING '.$havingStr;
	}

	/**
	 * 解析order
	 *
	 * @param      <type>  $order  The order
	 *
	 * @return     <type>  ( description_of_the_return_value )
	 */
	public static function parseOrder($order){
		$orderStr = '';
		if(is_string($order)&&!empty($order)){
			$orderStr = $order;
		}
		return empty($orderStr) ? '' : ' ORDER BY '.$orderStr;
	}

	/**
	 * 解析limit
	 *
	 * @param      <type>  $limit  The limit
	 *
	 * @return     <type>  ( description_of_the_return_value )
	 */
	public static function parseLimit($limit){
		$limitStr = '';
		if(is_array($limit)){
			$limitStr = implode(',', $limit);
		}elseif(is_string($limit)&&!empty($limit)){
			$limitStr = $limit;
		}
		return empty($limitStr) ? '' : ' LIMIT '.$limitStr;
	}

	/**
	 * 解析字段
	 *
	 * @param      <type>  $fields  The fields
	 *
	 * @return     string  ( description_of_the_return_value )
	 */
	public static function parseFields($fields){
		if(is_array($fields)){
			array_walk($fields, array('PdoMySQL','addSpecialChar'));
			$fieldsStr = implode(',', $fields);
		}elseif (is_string($fields)&&!(empty($fields))) {
			if(strpos($fields, '`')===false){
				$fields = explode(',', $fields);
				array_walk($fields, array('PdoMySQL','addSpecialChar'));
				$fieldsStr = implode(',', $fields);
			}else{
				$fieldsStr = $fields;
			}
		}else{
			$fieldsStr = "*";
		}
		return $fieldsStr;	
	}

	/**
	 * 通过反引号引用字字段
	 *
	 * @param      string  $value  The value
	 *
	 * @return     string  ( description_of_the_return_value )
	 */
	public static function addSpecialChar(&$value){
		if($value==="*"||strpos($value,'.')!==false||strpos($value,'`')!==false){
			//不用做处理
		}elseif(strpos($value, '`')===false){
			$value = '`'.trim($value).'`';
		}
		return $value;
	}

	/**
	 * 释放结果集
	 */
	public static function free(){
		self::$PDOStatement = null;
	}

	/**
	 * 抛出错误信息
	 *
	 * @return     boolean  ( description_of_the_return_value )
	 */
	public static function haveErrorThrowException(){
		$obj = empty(self::$PDOStatement) ? self::$link : self::$PDOStatement;
		$arrError = $obj->errorInfo();
		if($arrError[0]!='00000'){
			self::$error = 'SQLSTATE=>'.$arrError[0].'<br/>SQL Error=>'.$arrError[2].'<br/>Error SQL=>'.self::$queryStr;
			self::throw_exception(self::$error);
			return false;
		}
		if(self::$queryStr==''){
			self::throw_exception('没有执行SQL语句');
			return false;
		}
	}

	/**
	 * 自定义错误处理
	 *
	 * @param      <type>  $errMsg  The error message
	 */
	public static function throw_exception($errMsg){
		echo $errMsg;
	}

	/**
	 * 销毁连接对象，关闭数据库
	 */
	public static function close(){
		self::$link = null;
	}
}
$pdo = new PdoMysql();
var_dump($pdo->showTables());