对数据的读取 Read
	$m=new Model('User'); ##返回一个实例
	$m=M('User');
	select
	#调用实例下的方法
	$m->select();//获取所有数据,以数组形式返回

array (size=2)
  0 => 
    array (size=3)
      'id' => string '1' (length=1)
      'username' => string 'zhaotongzheng' (length=13)
      'sex' => string '1' (length=1)
  1 => 
    array (size=3)
      'id' => string '2' (length=1)
      'username' => string 'MM' (length=2)
      'sex' => string '0' (length=1)


find 方法:

	find
	$m->find($id);//获取单条数据
	

获取第一行数据,只返回一条数据
$arr=$m->find();
var_dump($arr);

获取Id=2的数据
$arr=$m->find(2);
var_dump($arr);



<?php
 class IndexAction extends Action {
	 function index(){
		 #$m=new Model('user');
		 $m=M('user');
		 #$arr=$m->select();
		 $arr=$m->find();
		 var_dump($arr);
		 #$this->assign('data',$arr);
		 #$this->display();
	 }

array (size=3)
  'id' => string '1' (length=1)
  'username' => string 'zhaotongzheng' (length=13)
  'sex' => string '1' (length=1)

find 只返回一条数据://获取单条数据



getField(字段名)//获取一个具体的字段值

$arr=$m->where('id=2')->getField('username');


添加数据:

	对数据的添加 Create
	$m=new Model('User');
	$m=M('User');
	$m->字段名=值
	$m->add();

	返回值是新增的id号

	$m->id=3;
	$m->username='scan';
	$m->sex=1;
	$m->add();


array (size=3)
  0 => 
    array (size=3)
      'id' => string '1' (length=1)
      'username' => string 'zhaotongzheng' (length=13)
      'sex' => string '1' (length=1)
  1 => 
    array (size=3)
      'id' => string '2' (length=1)
      'username' => string 'MM' (length=2)
      'sex' => string '0' (length=1)
  2 => 
    array (size=3)
      'id' => string '3' (length=1)
      'username' => string 'scan' (length=4)
      'sex' => string '1' (length=1)



    SHOW COLUMNS FROM `user` [ RunTime:0.004057s ]
    INSERT INTO `user` (`id`,`username`,`sex`) VALUES (3,'scan',1) [ RunTime:0.173630s ]
    SELECT * FROM `user` [ RunTime:0.001673s ]


删除数据:

$m->where('id=2')->delete(); //与上面效果相同,也是删除id为2的数据



更新数据:

$m=M('User');
	$data['id']=1;
	$data['username']='ztz2';
	$m->save($data);             
	返回值是受影响行数




<?php
 class IndexAction extends Action {
	 function index(){
		 #$m=new Model('user');
		 $m=M('user');
		 $arr=$m->select();
	     var_dump($arr);
		 $data['id']=1;
	     $data['username']='ztz2';
	     $m->save($data); 
		 $arr=$m->select();

		 var_dump($arr);
		 #$this->assign('data',$arr);
		 $this->display();
	 }
	 



array (size=2)
  0 => 
    array (size=3)
      'id' => string '1' (length=1)
      'username' => string 'ztz2' (length=4)
      'sex' => string '1' (length=1)
  1 => 
    array (size=3)
      'id' => string '2' (length=1)
      'username' => string 'MM' (length=2)
      'sex' => string '0' (length=1)

array (size=2)
  0 => 
    array (size=3)
      'id' => string '1' (length=1)
      'username' => string 'ztz2' (length=4)
      'sex' => string '1' (length=1)
  1 => 
    array (size=3)
      'id' => string '2' (length=1)
      'username' => string 'MM' (length=2)
      'sex' => string '0' (length=1)