yii2.0数据库交互ORM

ORM
Object  Relational  Mapping  对象关系映射

ObjectPHP
对象，属性

Relational
数据库表，字段

Mapping
对象和表的关系；属性与字段的关系 

自制ORM框架

在models文件夹下创建AOrm基类 AOrm.php

<?php
namespace  app\models;
abstract class AOrm{
public $tablename;
public $primaryKey='id';
public $id;

public abstract function Mapping();
/*
*  将对象持久化到数据库
*  如果id属性没有被赋值，那么执行插入操作，否则执行更新操作
*/
public  function  save(){

$sql=$this->buildSaveSql();
\yii::$app->db->createCommand($sql)->execute();
}

private function buildSaveSql(){
$sql='';
$mapping=$this->Mapping();
$fields=[];
$values=[];
if(empty($this->id)){
/*
* 没有id执行插入操作
* INSERT INTO table_name() values()
*/
foreach($mapping as $k=>$v){
if(isset($this->$k)){
/*
* mapping中的$k有uName,       pwd,        nName,      restMoney,
* mapping中的$v有username,    password,   nickname,   rest
* 所以$this->$k指向的是
*                      public $uName
*                      public $pwd
*                      public $nName
*                      public $restMoney
* isset($this->$k)表示这些变量是否有值；
* $this->$k需要在控制器中赋值，如： AomController下
*          $object=new BUser()
*          $object->nName='AORM';
*/
array_push($fields,$v);
array_push($values,"'{$this->$k}'");

}
}
return $sql='INSERT INTO '.$this->tablename.'('.implode(',',$fields).') VALUES('.implode(',',$values).')';
}else{
$set=[];
//更新操作 UPDATE table_name SET  field=value , field=value where id=
foreach($mapping as $k=>$v){
if(isset($this->$k)){
array_push($set, "{$v}='{$this->$k}'");
}
}
return $sql='UPDATE '.$this->tablename.' SET '.implode(',',$set).' WHERE '.$this->primaryKey.'='.$this->id;
}

}
public function del(){
if(!empty($this->id)){
\yii::$app->db->createCommand('DELETE FROM '.$this->tablename.' where '.$this->primaryKey.'='.$this->id)->execute();
}else{
return false;
}
}

}

创建子类文件models/BUser.php

<?php
namespace  app\models;
class BUser extends AOrm{
public $tablename='test';
public $id;
public $uName;
public $pwd;
public $nName;
public $restMoney;

public function Mapping()
{
// TODO: Implement Mapping() method.
return [
'uName'     =>'username',
'pwd'       =>'password',
'nName'     =>'nickname',
'restMoney' =>'rest'
];
}

}

在控制器中调用models/AOrm下的方法

<?php
namespace  app\controllers;
use app\models\BUser;
use yii\web\Controller;

class AomController extends Controller{

public function actionTest(){
$object= new BUser() ;
$object->uName='ORM';
$object->pwd='123456';
$object->nName='哈哈';
$object->id=4;
$res=$object->del();
echo "<pre>";
print_r($res);
}
}