tp5链表查询

//tp5连表查询
//首先生成链表的sql
//注意，两个表的字段的取出来顺序要一致，不能颠倒
$sql = Db::table('zhj_account_log')
       ->where(['user_id'=>$this->user_id,'wisdom_coin'=>0])
       ->union(function($query){
               $query->field("id as bill_id,CASE status WHEN 0 THEN CONCAT( '-',money) WHEN 2 THEN money END as money,create_time as add_time,CASE status WHEN 0 THEN '申请提现中' WHEN 2 THEN CONCAT(CONCAT('申请提现被拒绝(',remark),')') END as content")->where('status in (0,2) and user_id ='.$this->user_id)->table('zhj_withdrawals');
       },true)
       ->field("log_id as bill_id,user_money as money,change_time as add_time,content")
       ->buildSql();

//再从链表的sql查询特定字段和排序、limit
$result = Db::table($sql.' as a')->field("bill_id,money,FROM_UNIXTIME(add_time,'%Y年%m月%d日 %H:%i:%s') as addtime,content") 
          ->order('a.add_time DESC')
          ->page($page,$page_count)
          ->select();