Question

我有下表： ID ministry_id building_id action_date action_type 1 14 1653 2011-12-23 11:22:33 1 2 14 1653 2012-02-29 11:51:12 2 3 14 1653 2013-06-25 11:29:22 1 4 14 1653 2017-05-15 17:01:37 2

当我从这个表中选择时，它会返回以下结果：

ministry_id  building_id       add_date                   end_date
     14         1653        2011-12-23 11:22:33        2012-02-29 11:51:12
     14         1653        2013-06-25 11:29:22        2017-05-15 17:01:37

当action_type = 1时，action_date = add_date
当action_type = 2时，action_date = end_date

Answer 1

这是一个查询。我只在end_date＆gt; add_date

SELECT 
    t1.ministry_id,
    t1.building_id,
    t1.action_date as add_date,
    MIN(t2.end_date) as end_date
FROM yourTable t1
LEFT JOIN (
    SELECT t.action_date end_date, action_date
    FROM yourTable t
    WHERE t.action_type = 2 
    ) t2
    ON t1.action_date < t2.action_date
WHERE t1.action_type = 1
GROUP BY t1.action_date;

<强>示例

MariaDB [test]> select * from yourTable;
+-------------+-------------+---------------------+-------------+
| ministry_id | building_id | action_date         | action_type |
+-------------+-------------+---------------------+-------------+
|          14 |        1653 | 2011-12-23 11:22:33 |           1 |
|          14 |        1653 | 2012-02-29 11:51:12 |           2 |
|          14 |        1653 | 2013-06-25 11:29:22 |           1 |
|          14 |        1653 | 2017-05-15 17:01:37 |           2 |
+-------------+-------------+---------------------+-------------+
4 rows in set (0.00 sec)

MariaDB [test]> SELECT 
    -> t1.ministry_id,
    -> t1.building_id,
    -> t1.action_date as add_date,
    -> MIN(t2.end_date) as end_date
    -> FROM yourTable t1
    -> LEFT JOIN (
    -> SELECT t.action_date end_date, action_date
    -> FROM yourTable t
    -> WHERE t.action_type = 2 
    -> ) t2
    -> ON t1.action_date < t2.action_date
    -> WHERE t1.action_type = 1
    -> GROUP BY t1.action_date
    -> ;
+-------------+-------------+---------------------+---------------------+
| ministry_id | building_id | add_date            | end_date            |
+-------------+-------------+---------------------+---------------------+
|          14 |        1653 | 2011-12-23 11:22:33 | 2012-02-29 11:51:12 |
|          14 |        1653 | 2013-06-25 11:29:22 | 2017-05-15 17:01:37 |
+-------------+-------------+---------------------+---------------------+
2 rows in set (0.00 sec)

MariaDB [test]>

Answer 2

以下是使用id：

的答案

SELECT 
    t1.ministry_id,
    t1.building_id,
    t1.action_date as add_date,
    t2.action_date as end_date
FROM yourTable t1
LEFT JOIN yourTable t2
    ON t1.id+1 = t2.id
WHERE t1.action_type = 1;

<强>示例

MariaDB [test]> select * from yourTable;
+----+-------------+-------------+---------------------+-------------+
| id | ministry_id | building_id | action_date         | action_type |
+----+-------------+-------------+---------------------+-------------+
|  1 |          14 |        1653 | 2011-12-23 11:22:33 |           1 |
|  2 |          14 |        1653 | 2012-02-29 11:51:12 |           2 |
|  3 |          14 |        1653 | 2013-06-25 11:29:22 |           1 |
|  4 |          14 |        1653 | 2017-05-15 17:01:37 |           2 |
+----+-------------+-------------+---------------------+-------------+
4 rows in set (0.00 sec)

MariaDB [test]> SELECT 
    -> t1.ministry_id,
    -> t1.building_id,
    -> t1.action_date as add_date,
    -> t2.action_date as end_date
    -> FROM yourTable t1
    -> LEFT JOIN yourTable t2
    -> ON t1.id+1 = t2.id
    -> WHERE t1.action_type = 1;
+-------------+-------------+---------------------+---------------------+
| ministry_id | building_id | add_date            | end_date            |
+-------------+-------------+---------------------+---------------------+
|          14 |        1653 | 2011-12-23 11:22:33 | 2012-02-29 11:51:12 |
|          14 |        1653 | 2013-06-25 11:29:22 | 2017-05-15 17:01:37 |
+-------------+-------------+---------------------+---------------------+
2 rows in set (0.00 sec)

MariaDB [test]>

选择MySQL循环语句

2 个答案: