php - mysql 2 SELECT 在一个查询中

Question

我希望这两个 SELECT 查询给出一个结果，然后我想按date_time

选择 1：

"SELECT * FROM `table` WHERE `f_id` = '$uid' AND `t_id` = '$pid'"

选择 2：

"SELECT * FROM `table` WHERE `f_id` = '$pid' AND `t_id` = '$uid'"

我试图将它放在一个 WHERE 子句中，但这是不可能的，我也尝试将它们放在子查询中，但这使得 SELECT 2 加入正确的 SELECT 1 ：/ 我想要这两个查询的一个输出数组，按date_time. 这怎么可能？

Answer 1

SELECT * FROM `table` WHERE `f_id` = '$uid' AND `t_id` = '$pid'
UNION ALL
SELECT * FROM `table` WHERE `f_id` = '$pid' AND `t_id` = '$uid'

编辑：

呃……对不起，我没看到是同一张桌子。

SELECT * FROM table
  WHERE (`f_id` = '$uid' AND `t_id` = '$pid') OR (`f_id` = '$pid' AND `t_id` = '$uid')
  ORDER BY date_time

Answer 2

关于什么：

SELECT 
    * 
FROM 
    `table` 
WHERE 
    (`f_id` = '$uid' AND `t_id` = '$pid') OR 
    (`f_id` = '$pid' AND `t_id` = '$uid')
ORDER BY 
    `date_time` DESC

Answer 3

尝试这个

   SELECT * FROM 

      ( select * FROM `table` WHERE `f_id` = '$uid' AND `t_id` = '$pid'
       union all 
        SELECT * FROM `table` WHERE `f_id` = '$pid' AND `t_id` = '$uid' )t

   ORDER BY date_time