Question

我正在为某个私有站点创建数据库。在数据库中，我有一个名为times的表，可以在其中保存用户名和用户空闲的时间。桌子看起来像这样。

|uid |Monday|Tuesday |... |Saturday |Sunday |t12|t13|t14|...|t19|t20
_____________________________________________________________________

uid 是用户名， t12-t20 是小时（ t16 = 1 ， 星期一 = 1 表示该用户在星期一16点有空。

一行的示例为：

|alex1|1|1|0|0|0|0|1|0|0|0|0|0|1|1|1|1|

这意味着用户 alex1 在周一，周二和周日的17、18、19和20点免费。

表中可以有多个用户，某些用户可以有多个用户。像，用户alex1可以在更多行中具有不同的保存时间。（示例：一行意味着他在星期一和星期五15点以后有空，但在另一行中，他在星期六的14点，17点和20点有空）

示例：

gordon | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
gordon | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |

第一行表示：gordon用户在星期一和星期二12点是免费的。第二行表示：gordon用户在星期三13点是免费的

问题是：

如何进行遍历表格并给出结果的查询：

  Day    | t12 | t13 | t14 | t15 | t16 | t17 | t18 | t19 | t20 |
________________________________________________________________
Monday      5     4     8     8     8     4     0     0     4
Tuesday     2     2     2     2     2     1     0     0     2
Wednesday   10    10    10    2     8     10    8     7     7
Thursday    5     4     8     8     8     4     0     1     4
Friday      5     4     3     7     8     4     9     0     4
Saturday    8     9     8     3     9     4     3     0     4
Sunday      1     4     8     8     1     4     0     9     3

这意味着：星期一14点有8个免费用户，或星期五20点有4个免费用户。

Answer 1

一个更好的设计示例是使用如下表格：

availability

user day time
   1   1   16

这可能不是最好的解决方案，但是它对您当前的设置有很大的改进。

Answer 2

您可以计算按日计算的结果，然后按如下所示使用union-

SELECT 'Monday' AS Day,
SUM(t12) t12,SUM(t13) t13,SUM(t14) t14,SUM(t15) t15,SUM(t16) t16,
SUM(t17) t17,SUM(t18) t18,SUM(t19) t19,SUM(t20) t20
FROM your_table WHERE Monday = 1

UNION ALL

SELECT 'Tuesday' AS Day,
SUM(t12) t12,SUM(t13) t13,SUM(t14) t14,SUM(t15) t15,SUM(t16) t16,
SUM(t17) t17,SUM(t18) t18,SUM(t19) t19,SUM(t20) t20
FROM your_table WHERE Tuesday = 1

UNION ALL

SELECT 'Wednesday' AS Day,
SUM(t12) t12,SUM(t13) t13,SUM(t14) t14,SUM(t15) t15,SUM(t16) t16,
SUM(t17) t17,SUM(t18) t18,SUM(t19) t19,SUM(t20) t20
FROM your_table WHERE Wednesday = 1

UNION ALL

SELECT 'Thursday' AS Day,
SUM(t12) t12,SUM(t13) t13,SUM(t14) t14,SUM(t15) t15,SUM(t16) t16,
SUM(t17) t17,SUM(t18) t18,SUM(t19) t19,SUM(t20) t20
FROM your_table WHERE Thursday = 1

UNION ALL

SELECT 'Friday' AS Day,
SUM(t12) t12,SUM(t13) t13,SUM(t14) t14,SUM(t15) t15,SUM(t16) t16,
SUM(t17) t17,SUM(t18) t18,SUM(t19) t19,SUM(t20) t20
FROM your_table WHERE Friday = 1

UNION ALL

SELECT 'Saturday' AS Day,
SUM(t12) t12,SUM(t13) t13,SUM(t14) t14,SUM(t15) t15,SUM(t16) t16,
SUM(t17) t17,SUM(t18) t18,SUM(t19) t19,SUM(t20) t20
FROM your_table WHERE Saturday = 1

UNION ALL

SELECT 'Sunday' AS Day,
SUM(t12) t12,SUM(t13) t13,SUM(t14) t14,SUM(t15) t15,SUM(t16) t16,
SUM(t17) t17,SUM(t18) t18,SUM(t19) t19,SUM(t20) t20
FROM your_table WHERE Sunday = 1

如何计算列中的值并将每个列名称及其结果保存在一行中？

2 个答案: