Mysql sql语句自动拼接方法

<?php
/*燕十八 公益PHP培训  
课堂地址:YY频道88354001  
学习社区:www.zixue.it */

class Mysql{
            //拼接sql语句
        public function autoExecute($data='',$table,$mode = "insert",$where = "where 1 limit 1"){        
            //insert 和 update 语句需要传入数组判断
            if(is_array($data)){
                //Update语句的拼接
                if($mode == "update"){
                    $sql="update $table set ";
                    foreach($data as $key=>$val){
                        $sql.=$key ." = "."'$val'".',';
                    }
                    //循环后语句是$sql updata $table set filed1 = value1,filed2=value2,filed3=values3,
                    $sql=substr(trim($sql),0,-1).' '.$where;
                     //先将sql语句的首位空格去掉,然后将后面的','给去掉拼接$where条件
                     return $this->query($sql);
                }
                    //insert 语句的拼接,默认是insert
                    $sql = $mode . " into ".$table ." ( " . implode(',',array_keys($data));
                    $sql.=" ) value "."('".implode("','",array_values($data))."')";
                    return $this->query($sql);
            
            }else{
                    //delete 语句的拼接
                    //当语句为delete时候,此时$data传入是表名,$table传入的是delete $mode传入是where条件
                    if($table = 'delete'){
                        $sql="delete from ".$data.' '.$mode;
                        $this->query($sql);
                        return $this->affected_rows();                    
                    }else{
                            return false;
                    }
            }
        }

        //query方法
        public function query($sql){
            $res = mysql_query($sql);
            return $res;
        }
    }
        //+++++++++++++++自动拼接sql语句使用方法+++++++++++++++++++//

        $mysql = new Mysql();
        //insert 语句
        $data=array(
            'username'=>'demo',
            'password'=>'admin'
        );
        $mysql->autoExecute($data,'user表');

        //updata 语句
        $where = "where id > 10;";
        $mysql->autoExecute($data,'user表','update',$where);
        
        //delete 语句
        $mysql->autoExecute('user表','delete',$where);