php 仿thinkphp的sql类库

模仿thinkphp封装的类库

<?php
/**
 * MySql操作类2015版
 * 作者：咖啡兽兽   287962566@qq.com
 * 使用说明：
 *         //包含文件
 *         inclode 'Mysql.class.php';
 *         //写个方法来实例化数据库对象
 *         function newMySQL($table){
 *             //DSN参数，建议从配置文件获取
 *             $dsn = array(
 *                     'DB_HOST'        =>    'loaclhost',    //主机地址
 *                    'DB_NAME'        =>    'mydb',        //数据库名
 *                    'DB_PORT'        =>    3306,            //端口
 *                    'DB_PREFIX'        =>    'kf',            //表前缀
 *                    'DB_CHARSET'    =>    'utf8',            //数据库编码
 *                    'DB_USER'        =>    'root',            //用户名
 *                    'DB_PWD'        =>    '123456',    //密码
 *             );
 *             //表名
 *             $dsn['DB_TABLE'] = $table;
 *             //返回数据库对象
 *             return Mysql::start($dsn);
 *         }
 *         //传入表名，获取数据库对象
 *         $Sql = newMySQL('user');
 *         //若要切换操作表，可直接给table成员属性赋值
 *         $Sql->table = 'product';
 *         //插入数据
 *         $data['name'] = '小白';
 *         $data['pwd'] = md5('123456');
 *         $data['age'] = 25;
 *         $data['sex'] = '男';
 *         $Sql->add($data);
 *
 *         //更新数据
 *         $data['name'] = '小黑';
 *         $where = "id=1";
 *         $Sql->where($where)->save($data);
 *         //指定字段加1
 *         $Sql->where($where)->sum('age');
 *         //指定字段加N
 *         $Sql->where($where)->sum('age',10);
 *
 *         //查询数据
 *         $where = "sex='男' and age>20";
 *         //取回所有符合条件的数据
 *         $arr = $Sql->where($where)->select();
 *         //可用field指定要取回的字段
 *         $arr = $Sql->field('name,sex')->where($where)->select();
 *         //取回指定范围  limit  两个参数都是整数型
 *         $arr = $Sql->where($where)->limit(偏移量,最大行数)->select();
 *         //指定排序  desc  or  asc  可指定多个字段，以","隔开
 *         $arr = $Sql->where($where)->order("sex desc")->select();
 *         //取回第一行
 *         $find = $Sql->where($where)->find();
 *         //单独取回指定字段,若符合条件的数据 >1行，则返回数组
 *         $field = $Sql->where('id=1')->getField('name');
 *         //取符合条件的总行数
 *         $count = $Sql->where($where)->getCount();
 *
 *         //删除数据
 *         $Sql->where($where)->delete();
 */
class Mysql
{
    private $host;   //主机地址
    private $dbname; //数据库名
    private $port;  //数据库端口
    private $username; //用户名
    private $password; //密码
    private $charset; //数据库编码
    static $SQL; //数据库对象
    static $obj = null;
    public $table; //操作表
    private $pre = null;
    private $opt;  //选项

    /**
     * 初始化数据库
     * @param Array $dsn 数据库连接参数
     */
    private function __construct($dsn){
        $this->host = $dsn['DB_HOST'];
        $this->dbname = $dsn['DB_NAME'];
        $this->username = $dsn['DB_USER'];
        $this->password = $dsn['DB_PWD'];
        $this->port = $dsn['DB_PORT'];
        $this->charset = $dsn['DB_CHARSET'];
        //$this->table = $dsn['DB_PREFIX'].$dsn['DB_TABLE'];
        $this->opt['where'] = '';
        $this->opt['order'] = '';
        $this->opt['limit'] = '';
        $this->opt['field'] = null;
        $this->connect();
    }

    /*
     * Lee:
     * 还原默认纯洁的配置环境
     * */
    public function reset()
    {
        $this->opt['where'] = '';
        $this->opt['order'] = '';
        $this->opt['limit'] = '';
        $this->opt['field'] = null;
    }

    /**
     * 连接数据库
     * @return Bool
     */
    private function connect(){
        try{
             $dsn  =  'mysql:host='.$this->host.';dbname='.$this->dbname.';port='.$this->port;
             $options  = array(
                 PDO :: MYSQL_ATTR_INIT_COMMAND  =>  'SET NAMES '.$this->charset,
            );
             self::$SQL = new  PDO ($dsn,$this->username,$this->password,$options);
            //设置错误报告
            self::$SQL->setAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_EXCEPTION);
        }catch(PDOException $e){
            echo "数据库连接失败：".$e->getMessage();
            exit;
        }
        return true;
    }

    /**
     * @param Array $dsn 数据库连接参数(DB_HOST[主机],DB_NAME[数据库名],DB_PORT[端口],DB_CHARSET[编码],DB_USER[帐户],DB_PWD[密码],DB_TABLE[表名])
     * @return Object
     */
    static function start($dsn){
        //判断对象是否存在，若已存在则直接返回该对象
        //if(is_null(self::$obj)){
        self::$obj = null;
        self::$obj = new self($dsn);
        //}
        return self::$obj;
    }

    /**
     * 插入数据(成功返回新插入的 自动增长主键，失败返回0)
     * @param Array $data 欲插入的数据，对应表中的键与值
     * @param Int 0 准备语句 ,1 执行语句,2(默认)准备并执行语句
     * @return Int
     */
    public function add($data,$type = 2){
        try{
            //构造SQL语句
            $count = 0;
            $a = '';
            foreach($data as $k=>$v){
                if($count != 0){
                    $a = ',';
                }
                @$key .= $a.$k;
                @$bind .=$a.":$k";
                $count++;
            }
            $s = "insert into {$this->table}({$key}) values({$bind})";

            //发送语句
            if($type != 1){
                $this->pre = self::$SQL->prepare($s);
                if($type == 0 && is_object($this->pre) == true){
                    return 1;
                }
            }
            //执行语句
            if($type != 0){
                $this->pre->execute($data);
            }
            //重置各种条件
            $this->reset();
            //返回最新主键
            return self::$SQL->lastinsertid();
        }catch(PDOException $e){
            exit("错误：".$e->getMessage());
        }

    }
    /**
     * 更新数据(返回受影响行)
     * @param void $data 传入更新数组
     * @return Int
     */
    public function save($data){
        try{
            //构造SQL语句
            $count = 0;
            $a = '';
            foreach($data as $k=>$v)
            {
                if($count != 0){
                    $a = ',';
                }
                @$bind .=$a."$k='$v'";
                $count++;
            }
            $s = "update {$this->table} set {$bind} {$this->opt['where']}";
            //发送语句
            $this->pre = self::$SQL->prepare($s);
            //执行语句
            $this->pre->execute($data);
            //重置各种条件
            $this->reset();
            //返回受影响行
            return $this->pre->rowCount();
        }catch(PDOException $e){
            exit("错误：".$e->getMessage());
        }
    }

    /**
     * 指定字段加N，默认加1
     * @param String $key 字段
     * @param Int $num [可选]裕增加的数值，默认1
     * @return Int
     */
    public function sum($key,$num){
        try{
            $s = "update {$this->table} set {$key}={$key}+{$num} {$this->opt['where']}";    

            //发送语句
            $this->pre = self::$SQL->prepare($s);
            //执行语句
            $this->pre->execute();
            //返回受影响行
            return $this->pre->rowCount();
        }catch(PDOException $e){
            exit("错误：".$e->getMessage());
        }
    }

    /**
     * 删除数据(返回受影响行)
     * @return Int
     */
    public function delete(){
        try{
            $s = "delete from {$this->table} {$this->opt['where']}";
            //发送语句
            $this->pre = self::$SQL->prepare($s);
            //执行语句
            $this->pre->execute();
            //返回受影响行
            return $this->pre->rowCount();
        }catch(PDOException $e){
            exit("错误：".$e->getMessage());
        }
    }

    /*
     * Lee函数：
     * 只推荐不存在任何参数的sql语句使用该函数
     * */
    public  function query($str)
    {
        try
        {
            $s = $str;
            //发送语句
            $this->pre = self::$SQL->prepare($s);
            //执行语句
            $this->pre->execute();
            //设置返回关联数组
            $this->pre->setFetchMode(PDO::FETCH_ASSOC);
            //重置各种条件
            $this->reset();
            return $this->pre->fetchAll();
        }
        catch(PDOException $e)
        {
           exit("错误：".$e->getMessage());
        }
    }

    /*
     * Lee函数：
     * 只推荐不存在任何参数的sql语句使用该函数
     * */
    public  function send($str)
    {
        try
        {
            $s = $str;
            //发送语句
            $this->pre = self::$SQL->prepare($s);
            //执行语句
            $this->pre->execute();
            //重置各种条件
            $this->reset();
        }
        catch(PDOException $e)
        {
            exit("错误：".$e->getMessage());
        }
    }

    /**
     * 取数据集(返回符合条件的所有数据)
     * @return array
     */
    public function select(){
        try{
            $s = "select ".($this->opt['field']? $this->opt['field']:'*')." from {$this->table} {$this->opt['where']} {$this->opt['order']} {$this->opt['limit']}";

            //发送语句
            $this->pre = self::$SQL->prepare($s);
            //执行语句
            $this->pre->execute();
            //设置返回关联数组
            $this->pre->setFetchMode(PDO::FETCH_ASSOC);
            //重置各种条件
            $this->reset();
            return $this->pre->fetchAll();
        }
        catch(PDOException $e)
        {
            exit("错误：".$e->getMessage());
        }
    }
    /**
     * 取一行数据(只返回第一条数据)
     * @return array
     */
    public function find(){
        try{
            $s = "select ".($this->opt['field']? $this->opt['field']:'*')." from {$this->table} {$this->opt['where']} {$this->opt['order']} limit 1";

            $this->pre = self::$SQL->prepare($s);
            //执行语句
            $this->pre->execute();
            //设置返回关联数组
            $this->pre->setFetchMode(PDO::FETCH_ASSOC);
            $arr = $this->pre->fetchAll();
            //重置各种条件
            $this->reset();
            return @$arr[0];
        }catch(PDOException $e){
            exit("错误：".$e->getMessage());
        }
    }
    /**
     * 取指定字段值(当只有一条数据时，直接返回键值，否则返回数组,失败返回false)
     * @param String $key 指定字段名
     * @return mixed
     */
    public function getField($key){
        $opt['field'] = $key;
        $selArr = $this->select();
        foreach($selArr as $number=>$value){
            $retuls[$number] = $value[$key];
        }

        if(@$retuls == null) $retuls=false;
        //判断是否单只有一条数据
        if(count($retuls) == 1 and $retuls != false){
            $retuls = $retuls[0];
        }
        return $retuls;
    }

    /**
     * 设定指定字段值
     * @param String $key 指定字段名
     * @param mixed $value 字段值
     * @return mixed
     */
    public function setField($key,$value){
        return $this->save(array($key=>$value));
    }

    /**
     * 取符合条件的数据总行数
     */
    public function getCount(){
        try{
            $s = "select count(*) from {$this->table} {$this->opt['where']}";
            $this->pre = self::$SQL->prepare($s);
            //执行语句
            $this->pre->execute();
            $count = $this->pre->fetch();
            return Intval($count[0]);
        }catch(PDOException $e){
            exit("错误：".$e->getMessage());
        }
    }
    /**
     * 查询条件
     * @param String $where 查询条件
     * @return this
     */
    public function where($where){
        $this->opt['where'] = $where? "where ".$where:'';
        return $this;
    }

    /**
     * 指定排序
     * @param String $order 排序规则  desc.倒序    asc.正序
     * @return this
     */
    public function order($order){
        $this->opt['order'] = $order? "order by ".$order:'';
        return $this;
    }

    /**
     * 指定欲取的数据条数
     * @param Int $min 只传一个参数时，传入欲取的数据条数；否则传入记录偏移量，从0开始
     * @param Int $max 欲取的的数据条数
     * @return this
     */
    public function limit($min,$max=null){
        $this->opt['limit'] = "limit ".intval($min).($max? ','.intval($max):'');
        return $this;
    }

    /**
     * 指定欲取的字段
     * @param String $field 指定字段名称，多个请以(,)分号隔开
     * @param this
     */
    public function field($field){
        $this->opt['field'] = $field;
        return $this;
    }

}

?>