Question

我有2张桌子

deposits 
id  |userId | amount|   Date
1   |  2    |  150  |   2013-11-22 02:57:00
2   |  3    |  230  |   2013-11-25 03:19:00

withdrawals 
id  |userId | amount|   Date
1   |  2    |  150  |   2013-11-23 02:57:00
2   |  3    |  190  |   2013-11-27 02:27:00

我想创建一个视图，以这种格式显示来自两个表的数据优选地，记录应该按日期字段排序，但这并不重要，因为我可以按日期查询查看视图。

depositsAndWithdrawal
type        |   id  | userId| amount    |   Date
deposit     |   1   |  2    |     150   |   2013-11-22 02:57:00
withdrawal  |   1   |  2    |     150   |   2013-11-23 02:57:00
deposit     |   2   |  3    |     230   |   2013-11-25 03:19:00
withdrawal  |   2   |  3    |     190   |   2013-11-27 02:27:00

这甚至可能吗？或者我是否需要创建一个新表并使用on insert事件向该表添加相关行？

Answer 1

您正在寻找union all查询。你可以在MySQL视图中执行此操作：

create view v as
    select  'deposit' as which, id, userId, amount, Date
    from deposits 
    union all
    select  'withdrawals' as which, id, userId, amount, Date
    from withdrawals ;

Answer 2

以下内容（原谅小错误）：

create view depositsAndWithdrawal as
(
   select 'deposits' as type, id, userID, amount, date 
   from deposits 
   UNION
   select 'withdrawls' as type, id, userID, amount, date 
   from widthdrawls
)

然后您可以使用以下方式查询：

select * from  depositsAndWithdrawal order by date;

不幸的是，我不认为您可以拥有视图顺序，因为您需要在视图中使用临时表，例如：

不起作用：

create view depositsAndWithdrawal as
    (
       select * from
       (select 'deposits' as type, id, userID, amount, date 
       from deposits 
       UNION
       select 'withdrawls' as type, id, userID, amount, date 
       from widthdrawls) as temp order by date
    )

但您可以将问题分成两个视图：

create view depositsAndWithdrawalTemp as
    (
       select 'deposits' as type, id, userID, amount, date 
       from deposits 
       UNION
       select 'withdrawls' as type, id, userID, amount, date 
       from widthdrawls
    )

create view depositsAndWithdrawal as
select * from depositsAndWithdrawalTemp order by date;

MYSQL创建视图，显示来自两个表的数据

2 个答案: