如何从另一个表中正确总结为“生病时间” - mysql

Question

在 mysql 数据库中，我创建了“Sickness”表：

    +--------+---------+---------+-------------+---------+-------------------------------+
    | Id_SICK|ID_WORKER| FNAME   | LNAME   | BEGIN_DATE          | END_DATE              |
    +--------+---------+---------+---------+------------+--------------------+-----------+
    | 4      |   26    | ANDREW  | WORM    |2019-03-19 07:00:00  |2019-03-19 15:00:00    |  
    +--------+---------+---------+----------------------+--------------------+-----------+  
    | 5      |   25    | ADAM    | GAX     |2019-03-21 07:00:00  |2019-03-21 15:00:00    |  
    +--------+---------+---------+----------------------+--------------------------------+  

“工人”表：

+--------+---------+---------+--
|ID_WORKER |  FNAME  | LNAME   |
+----------+---------+----------
| 25       |  ADAM   |  GAX    |
+----------+---------+----------
| 26       |  ANDREW |  WORM   |
+----------+---------+----------

“订单”表：

+--------+---------+---------+------------+
|ID_ORDER  |  DESC_ORDER  | NUMBER_ORDER  |
+----------+---------+--------------------+
| 20       |  TEST        |  TEST         |
+----------+---------+--------------------+

和“Order_status”表：

+--------+---------+---------+---------+-------------+--------+----------+------------+
| Id_status|ID_WORKER| ID_ORDER| BEGIN_DATE          | END_DATE          | ORDER_DONE |
+----------+---------+---------+----------+------------+---------+--------------------+
| 47       |   25    |    20   |2019-03-18 06:50:35  |2019-03-18 15:21:32|  NO        |
+----------+---------+---------+------------+---------+-------------------+-----------+ 
| 48       |   25    |    20   |2019-03-20 06:44:12  |2019-03-20 15:11:23|  NO        |
+----------+---------+---------+------------+---------+-------------------+-----------+ 
| 50       |   25    |    20   |2019-03-22 06:50:20  |2019-03-22 12:22:33|  YES        |
+----------+---------+---------+------------+---------+-------------------+-----------+ 
| 51       |   26    |    20   |2019-03-18 06:45:11  |2019-03-18 15:14:45|  NO        |
+----------+---------+---------+------------+---------+-------------------+-----------+ 
| 52       |   26    |    20   |2019-03-20 06:50:22  |2019-03-20 15:10:32|  NO       |
+----------+---------+---------+------------+---------+-------------------+-----------+ 
| 53       |   25    |    20   |2019-03-22 06:54:11  |2019-03-22 11:23:45|  YES       |
+----------+---------+---------+------------+---------+-------------------+-----------+ 

我想总结订单上每个其他工人的“总时间”（在 order_status 表中），包括总结 Sickness 表中的“病假时间”。我已经正确地选择了工人（LNAME，FNAME）订单（DESC_ORDER 和 NUMBER_ORDER）和“TOTAL TIME”从其他工人的订单。但我无法总结生病时间。我在下面写了mysql命令：

SELECT workers.FNAME, workers.LNAME, orders.NUMBER_ORDER, orders.DESC_ORDER, SEC_TO_TIME(SUM(TIME_TO_SEC(order_status.END_DATE) - TIME_TO_SEC(order_status.BEGIN_DATE))) AS 'TOTAL TIME', SEC_TO_TIME(SUM(TIME_TO_SEC(sickness.END_DATE) - TIME_TO_SEC(sickness.BEGIN_DATE))) AS 'SICKNESS TIME' FROM order_status INNER JOIN workers ON workers.ID_WORKER = order_status.ID_WORKER INNER JOIN orders ON orders.ID_ORDER = order_status.ID_ORDER INNER JOIN sickness ON sickness.ID_WORKER = workers.ID_WORKER WHERE orders.NUMBER_ORDER LIKE 'TEST' GROUP BY workers.ID_WORKER

然后我得到了结果：

+--------+---------+---------+-------+------------+------------+-------------+
|  FNAME  | LNAME   |  NUMBER_ORDER  | DESC_ORDER | TOTAL TIME | SICKNESS_TIME|
+----------+---------+---------------+------------+------------+-------------+
|  ADAM   |  GAX    | TEST           | TEST       | 22:25:38   |   24:00:00   |
+----------+---------+---------------+------------+------------+-------------+
|  ANDREW |  WORM   | TEST           | TEST       | 22:52:12   |   24:00:00   |
+----------+---------+---------------+------------+------------+-------------+

至于“生病时间不正确”是因为从“生病”分组后的ID_SICK是

+--------+---------+-----+
| Id_SICK| SICKNESS TIME |
+--------+---------+-----+
| 4      |   08:00:00    |  
+--------+---------+-----+ 
| 5      |   08:00:00    |   
+--------+---------+-----+  

例如，我也总结了“TOTAL TIME + SICKNESS TIME”

TOTAL TIME: 22:25:38 
SICKNESS TIME: 8:00:00

TOTAL + SICKNESS TIME : 22;25:38 + 8:00:00 = 30:25:38

有人可以帮我如何处理吗？我应该写什么样的mysql查询？有任何想法吗？感谢您的帮助:)

Answer 1

这实际上是预期的。上面的查询是连接 4 个表：

• 订单状态
• 疾病
• 工人
• 订单

“workers”表与“order_status”有1:N关系。

“workers”也与疾病有1:N关系，其实即使是1:1也没关系。

该查询正在上述表之间创建笛卡尔积，并且每个表中的重复列值可以在上述查询的结果集中。

删除group by 和sum 以查看结果集。

例如，在您的 id_worker 25 示例中，您有 3 个 order_status 行加入了 1 个疾病行（此行值将重复 3 次），加入了 1 个工人行（他们将再次重复 3 次），加入了 1 个订单行（相同）。

所以聚合函数sum 合并了重复值。

这只有在结果集包含用于聚合函数的所有列的唯一行时才有效

要解决这个问题，请使用子查询来聚合结果：

SELECT workers.fname, 
       workers.lname, 
       order_statusAgg.number_order,
       workers.id_worker,
       order_statusAgg.desc_order, 
       SEC_TO_TIME(SUM(order_statusAgg.stime)) AS 'TOTAL TIME', 
       SEC_TO_TIME(SUM(sicknessAgg.stime)) AS 'SICKNESS TIME' 
FROM   workers 
INNER JOIN (
SELECT sickness.id_worker, SUM((Time_to_sec(sickness.end_date) - 
                       Time_to_sec(sickness.begin_date))) AS stime
FROM sickness
GROUP BY sickness.id_worker
) sicknessAgg
               ON sicknessAgg.id_worker = workers.id_worker
       INNER JOIN (
SELECT order_status.id_worker, orders.number_order, orders.desc_order, SUM((Time_to_sec(order_status.end_date) - 
                       Time_to_sec(order_status.begin_date))) AS stime
FROM order_status
           INNER JOIN orders 
               ON orders.id_order = order_status.id_order
GROUP BY order_status.id_worker
) order_statusAgg
               ON workers.id_worker = order_statusAgg.id_worker 

WHERE  order_statusAgg.number_order LIKE 'TEST'
GROUP BY workers.id_worker

请注意，在这种情况下，需要从 workers 表开始，因为您希望从 order_status 和 sickness 表聚合不同数量的行。

参考资料：

How to join three tables to get Sum

MySQL JOIN with multiple tables and SUMS

How get the sum of two tables value using inner join