摘要：最近在做項(xiàng)目時(shí)用到了操作數(shù)據(jù)庫，于是自己寫了一個(gè)類文件，命名為文件代碼如下常量聲明數(shù)據(jù)庫地址數(shù)據(jù)庫名數(shù)據(jù)庫地址與數(shù)據(jù)庫名及編碼數(shù)據(jù)庫用戶名用戶名數(shù)據(jù)庫密碼密碼私有變量聲明語句緩存數(shù)據(jù)庫連接結(jié)果名稱建立連接屬性私有創(chuàng)建連接名稱執(zhí)行語句屬性

最近在做項(xiàng)目時(shí)用到了PDO操作mysql數(shù)據(jù)庫，于是自己寫了一個(gè)類文件，命名為mysql_class.php文件代碼如下：

link = new PDO(self::DSN, self::USERNAME, self::PASSWD, array(PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION));//創(chuàng)建連接
        }
        catch (PDOException $e) {
            die ("Error!:".$e->getMessage()."
");
        }
    }
    
    /*******************************************************************************
     * @ 名稱：執(zhí)行sql語句
     * @ 屬性：私有
     * @ 入口參數(shù)：無
     * @ 出口參數(shù):執(zhí)行成功返回真，否則返回假，查詢語句存儲(chǔ)結(jié)果集數(shù)組
    *******************************************************************************/
    private function sql(){
        try {
            $this->connect();
            $this->link->beginTransaction();//開啟一個(gè)事務(wù)
            $prepare = $this->link->prepare($this->sql);//準(zhǔn)備查詢語句
            $prepare->execute();//執(zhí)行查詢語句并返回結(jié)果集
            $cmd = strtolower(substr(trim($this->sql),0,6));//截取命令字符
            if($cmd == "select"){
                $array = $prepare->fetch(PDO::FETCH_ASSOC);//獲取結(jié)果集中的所有數(shù)據(jù)
                if(count($array)){
                    $this->result = NULL;
                    $this->result = $array;//存儲(chǔ)結(jié)果集
                    return true;//查詢到結(jié)果返回真
                }else{
                    return false;//否則返回假
                }
            }else if($cmd == "insert" || $cmd == "delete" || $cmd == "update"){
                if($prepare){
                    return true;//執(zhí)行成功返回真
                }else{
                    return false;//否則返回假
                }
            }
            $this->link->commit(); //如果正確執(zhí)行完成那么確認(rèn)commit
        } catch (PDOException $e) {
            $this->link->rollBack();//如果執(zhí)行中有錯(cuò)誤的情況下回滾
            die ("Error!:".$e->getMessage()."
");
        }
    }
    
    /*******************************************************************************
     * @ 名稱：sql語句處理
     * @ 屬性：公有
     * @ 入口參數(shù)：cmd增刪改查字符命令；dsname數(shù)據(jù)表名；first第一個(gè)參數(shù)；second第二個(gè)參數(shù)；
     * @ 出口參數(shù)：執(zhí)行成功返回真，否則返回假，查詢操作返回結(jié)果集數(shù)組
     * @ 使用示例：
        $mysql->handle("insert","abc","openid,nickname",""123","abc"");//增加
        $mysql->handle("delete","abc","openid="123"");//刪除
        $mysql->handle("update","abc","nickname="def"","openid="123"");//更新
        $res = $mysql->handle("select","abc","*","openid="123"");//查詢
        if(is_array($res) == true){
            foreach($res as $key=>$val){
                echo $key."=".$val."
";
            }
        }//遍歷查詢結(jié)果數(shù)組
    *******************************************************************************/
    public function handle($cmd,$dsname,$first,$second=NULL){
        switch($cmd){
            case "insert"://插入
                $this->sql = "insert into $dsname ($first) values ($second)";
                break;
            case "delete"://刪除
                $this->sql = "delete from $dsname where $first";
                break;
            case "update"://更新
                $this->sql = "update $dsname set $first where $second";
                break;
            case "select"://查詢
                $this->sql = "select $first from $dsname where $second";
                break;
            default:
                die ("Syntax Error!");//提示語法錯(cuò)誤
                break;
        }
        
        $res = $this->sql();//執(zhí)行sql語句
        if($res){
            if($cmd == "select"){
                return $this->result;//返回查詢結(jié)果
            }else{
                return true;//執(zhí)行成功返回真
            }
        }else{
            return false;//否則返回假
        }
        $this->link=NULL;;//關(guān)閉數(shù)據(jù)庫
    }
}

$mysql = new mysql;//數(shù)據(jù)庫類的實(shí)例化

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