Mysql-创建视图合并了2个表，但仅通过select合并，不合并表

在MySQL中，我有两个表，分别是

table\u retrieve

和

table\u bonus

表\u折扣

（有3列相同，2列不同）

表\u奖金

（有3个相同的列，3个不同的列）

我需要在PHP（CI）视图中选择3个相同的列作为1个表

我该怎么做？它不需要合并，但需要像合并表一样打印，并且可以按（a_时间和b_时间）升序排序

EXPLAIN select (@rn := @rn + 1) as id, `from`, `values`, `time`
from ((select 'rebate' as `from`, a_value as `values`, a_time as `time`
       from table_rebate
      ) union all
      (select 'bonus' as `from`, b_value, b_time
       from table_bonus
      ) 
     ) br cross join
     (select @rn := 0) params
order by `time`;

---

您可以使用

union all

：

select (@rn := @rn + 1) as id, `from`, `values`, `time`
from ((select 'rebate' as `from`, a_value as `values`, a_time as `time`
       from table_rebate
      ) union all
      (select 'bonus' as `from`, b_value, b_time
       from table_bonus
      ) 
     ) br cross join
     (select @rn := 0) params
order by `time`;

---

请注意，

from

、

值

和

时间

都是SQL中的关键字（即使没有保留）。这使得列的名称非常糟糕。

我有一个相同的问题，关于

表\u奖金

我应该将

b\u值声明为“值”

，将

b\u时间声明为“时间”

？对不起，什么是

@rn

？谢谢戈登。因为我需要加入4个表，所以

@rn

是否适用于4个表？@Cendana。对您可能需要使用另一个子查询和

order by

来获得正确的排序。非常感谢gordon，我将尝试将其合并。选择use

union all

是否会导致explain all NULL？

Number    from       Values            Time
  1      Rebate       1000      2018-05-05 10:25:15
  2      Bonus         500      2018-05-05 11:20:15
  3      Bonus         700      2018-05-05 11:35:15
  4      Rebate       3000      2018-05-05 12:30:15

EXPLAIN select (@rn := @rn + 1) as id, `from`, `values`, `time`
from ((select 'rebate' as `from`, a_value as `values`, a_time as `time`
       from table_rebate
      ) union all
      (select 'bonus' as `from`, b_value, b_time
       from table_bonus
      ) 
     ) br cross join
     (select @rn := 0) params
order by `time`;

select (@rn := @rn + 1) as id, `from`, `values`, `time`
from ((select 'rebate' as `from`, a_value as `values`, a_time as `time`
       from table_rebate
      ) union all
      (select 'bonus' as `from`, b_value, b_time
       from table_bonus
      ) 
     ) br cross join
     (select @rn := 0) params
order by `time`;