CI框架中封装Model

CI框架是一个轻量级、满足快速开发的php框架，本例对model的常用操作进行了封装，主要是对数据库的操作：

首先new一个基础的model类，继承自CI框架的CI_Model：

<?php

/**
 * Class M_model
 * base model @xwlyun
 */
class M_model extends CI_Model{

	/**
	 * 该Model对应的表名
	 * @var string
	 */
	var $table = '';

	/**
	 * 该Model对应的主键名
	 * @var string
	 */
	var $primaryKey = 'id';

	public function __construct(){
		parent::__construct();
		$this->load->database();
	}

#region 通用操作
	/**
	 * 执行sql @xwlyun
	 * @param $sql
	 * @param bool $affect_num 是否返回影响行数
	 * @return mixed
	 */
	function query($sql,$affect_num=false){
		$query = $this->db->query($sql);
		if($affect_num){
			$query = $this->db->affected_rows();
		}
		return $query;
	}

	/**
	 * 返回多行数据 @xwlyun
	 * @param $sql
	 * @return mixed
	 */
	function getRows($sql){
		$query = $this->db->query($sql);
		return $query->result_array();
	}

	/**
	 * 返回单行数据 @xwlyun
	 * @param $sql
	 * @return mixed
	 */
	function getRow($sql){
		$data = $this->getRows($sql);
		return $data[0];
	}

	/**
	 * 返回单行首列数据 @xwlyun
	 * @param $sql
	 * @return mixed
	 */
	function getOne($sql){
		$data = $this->getRow($sql);
		return current($data);
	}

	/**
	 * 插入数据 @xwlyun
	 * @param $data 插入的数据array
	 * @param string $table 表名
	 * @param bool $return 是否需要返回插入成功的id
	 * @return bool
	 */
	function insert($data, $table='', $return = false){
		if(!$table){
			if(!$this->table){
				return false;
			}
			$table = $this->table;
		}
		$query = $this->db->insert($table, $data);
		if($return){
			$query = $this->db->insert_id();
		}
		return $query;
	}

	/**
	 * 删除数据 @xwlyun
	 * @param $where where (e.g. array('field' =>'value',...))
	 * @param string $table
	 * @return bool
	 */
	function delete($where, $table='',$limit=1){
		if(!$table){
			if(!$this->table){
				return false;
			}
			$table = $this->table;
		}
		$this->db->where($where);
		$this->db->limit($limit);
		$this->db->delete($table);
	}

	/**
	 * 更新数据 @xwlyun
	 * @param $where where (e.g. array('field' =>'value',...))
	 * @param $update update (e.g. array('field' =>'value',...))
	 * @param string $table
	 * @param int $limit
	 * @return bool
	 */
	function update($where,$update,$table='',$limit=1){
		if(!$table){
			if(!$this->table){
				return false;
			}
			$table = $this->table;
		}
		$this->db->where($where);
		$this->db->limit($limit);
		$this->db->update($table, $update);
		return $this->db->affected_rows();
	}
#endregion

#region ci框架链式
	/**
	 * where (e.g. array('field' =>'value',...)) @xwlyun
	 * @param array $where
	 * @return $this
	 */
	function where($where=array()){
		foreach($where as $k=>$v){
			$this->db->where($k, $v);
		}
		return $this;
	}

	/**
	 * limit $offset,$limit @xwlyun
	 * @param int $limit
	 * @param int $offset
	 * @return $this
	 */
	function limit($limit=1,$offset=0){
		$this->db->limit($limit,$offset);
		return $this;
	}

	/**
	 * order by (e.g. array('field1'=>'asc',...)) @xwlyun
	 * @param array $orderby
	 * @return $this
	 */
	function orderby($orderby=array()){
		if($orderby){
			foreach($orderby as $k=>$v){
				$this->db->order_by($k, $v);
			}
		}else{
			$this->db->order_by($this->primaryKey, 'asc');
		}
		return $this;
	}

	/**
	 * where in (e.g. array('field1'=>array('value1','value2',...))) @xwlyun
	 * @param array $wherein
	 * @return $this
	 */
	function wherein($wherein=array()){
		if($wherein){
			foreach($wherein as $k=>$v){
				$this->db->where_in($k, $v);
			}
		}
		return $this;
	}

	/**
	 * where not in (e.g. array('field1'=>array('value1','value2',...))) @xwlyun
	 * @param array $wherenotin
	 * @return $this
	 */
	function wherenotin($wherenotin=array()){
		if($wherenotin){
			foreach($wherenotin as $k=>$v){
				$this->db->where_not_in($k, $v);
			}
		}
		return $this;
	}

	/**
	 * 获取总数 @xwlyun
	 * @return mixed
	 */
	function count(){
		$this->db->from($this->table);
		return $this->db->count_all_results();
	}

	/**
	 * select (e.g. array('field1','field2',...) or 'filed1,filed2,...') @xwlyun
	 * @param string $select
	 * @return mixed
	 */
	function select($select="*"){
		// select
		$this->db->select($select);
		// get
		$query = $this->db->get($this->table);
		// return
//		if($this->limit == 1){
//			$data = $query->row_array();
//		}else{
		$data = $query->result_array();
//		}
		return $data;
	}
#endregion

}

在使用时，比如我们有一张shops表，new一个model对其进行数据操作：

<?php

/**
 * Class Shop_model
 * shop model @xwlyun
 */
class Shop_model extends M_model{

	var $table = 'shops';

	public function __construct(){
		parent::__construct();
	}

	/**
	 * 验证有效店铺id @xwlyun
	 * @param $shop_id 店铺id
	 * @return bool
	 */
	function existsId($shop_id)
	{
		$where = array(
			$this->primaryKey	=>	intval($shop_id),
			'state'				=>	1,
		);
		$data = $this->where($where)->select();
		return $data[0];
	}

	/**
	 * 验证用户是否已经有开启的店铺 @xwlyun
	 * @param $user_id 用户id
	 * @return bool
	 */
	function checkUserShop($user_id){
		$where = array(
			'user_id'	=>	intval($user_id),
			'state'		=>	1,
		);
		$data = $this->where($where)->select();
		return $data[0];
	}

}

这里的model继承自封装好的M_model，可以在CI框架的config/autoload.php中自动加载这个model：

$autoload['model'] = array('common/m_model');