case when進行數據統計

SELECT 
SUM(CASE WHEN `status` = '1'  THEN 1 ELSE 0 END) AS waitpay,
SUM(CASE WHEN `group_done` = '1' AND `status` = 0 THEN 1 ELSE 0 END) AS waitgroup,
SUM(CASE WHEN `status` = '3' THEN 1 ELSE 0 END) AS waitreceive,
SUM(CASE WHEN `status` = '4' AND `comment` = 1 THEN 1 ELSE 0 END) AS waitcomment,
SUM(CASE WHEN `back_status` <> '0' THEN 1 ELSE 0 END) AS aftersell
 FROM `order`  WHERE uid = 145 AND `is_del` = 0 AND `close_reason` = 0`user`

/**
     * 統計訂單的數量
     */
    public function getStatOrderNum() {
        $needParam = array(
            'openId'=>array('code'=>1,'msg'=>'缺少參數')
        );
        $this->regArguments($needParam,$this->param);
        if($this->outData['code']){
            $this->printOut();
        }
        $uModel = new UserModel();
        $uid = $uModel->getUidByOpenId($this->param['openId']);
        if(!$uid){
            $this->outData['code'] = 1;
            $this->outData['msg']    = '賬號異常，請聯系客服人員';
            $this->printOut();
        }

        // 獲取待付款，待成團，待收貨，待評價，售后訂單的數量

        $sql = "SELECT";
        $sql .=" SUM(CASE WHEN `status` = '1'  THEN 1 ELSE 0 END) AS waitpay,";
        $sql .=" SUM(CASE WHEN `group_done` = '1' AND `status` = 0 THEN 1 ELSE 0 END) AS waitgroup,";
        $sql .=" SUM(CASE WHEN `status` = '3' THEN 1 ELSE 0 END) AS waitreceive,";
        $sql .=" SUM(CASE WHEN `status` = '4' AND `comment` = 1 THEN 1 ELSE 0 END) AS waitcomment,";
        $sql .=" SUM(CASE WHEN `back_status` <> '0' THEN 1 ELSE 0 END) AS aftersell";
        $sql .=" FROM `order`  WHERE uid = ".$uid." AND `is_del` = 0 AND `close_reason` = 0";


        $orderModel = new OrderModel();
        $res = $orderModel->query($sql);
        $this->outData['data'] = $res[0];
        $this->printOut();
    }

一條sql語句，省去很多代碼。