Question

来自这样的表格

----------------------------------
| User | TimeStamp         | Kind|
----------------------------------
| bob  |2015-01-19 03:14:16| err |
| bob  |2015-01-20 02:07:18|  ok | <-- from here |
| bob  |2015-01-21 12:07:18| err |               | 
| bob  |2015-01-22 12:08:26|  ok |               |
| bob  |2015-01-22 13:40:04| err | <-- to here   |
| bob  |2015-01-23 20:07:00|  ok |
| tom  |2015-01-19 03:14:16| err |
| tom  |2015-01-20 02:07:18|  ok | <-- from here|
| tom  |2015-01-22 13:40:04| err | <-- to here  |
| tom  |2015-01-23 20:07:00|  ok |

如何从第一个行获取Kind = ok 到 last 且Kind = 错误

预期结果：

----------------------------------
| User | TimeStamp         | Kind|
----------------------------------
| bob  |2015-01-20 02:07:18|  ok |
| bob  |2015-01-21 12:07:18| err |
| bob  |2015-01-22 12:08:26|  ok |
| bob  |2015-01-22 13:40:04| err |
| tom  |2015-01-20 02:07:18|  ok | 
| tom  |2015-01-22 13:40:04| err |

表中没有唯一的ID，但是时间戳是有序的

编辑：可以有多个用户

Answer 1

您可以使用以下查询：

SELECT User, TimeStamp, Kind
FROM mytable
WHERE TimeStamp BETWEEN (SELECT MIN(TimeStamp)
                         FROM mytable
                         WHERE Kind = 'ok')
                AND
                        (SELECT MAX(TimeStamp)
                         FROM mytable
                         WHERE Kind = 'err')

如果要将上述查询应用于涉及多个User值的数据，则必须在子查询中使用相关性，以便获得MIN和{{1每个用户：

MAX

或者，您可以使用SELECT User, TimeStamp, Kind FROM mytable AS t1 WHERE TimeStamp BETWEEN (SELECT MIN(t2.TimeStamp) FROM mytable AS t2 WHERE t1.User = t2.User AND t2.Kind = 'ok') AND (SELECT MAX(t3.TimeStamp) FROM mytable AS t3 WHERE t1.User = t3.User AND t3.Kind = 'err')：

INNER JOIN

选择从第一个到最后一个外观的数据范围

1 个答案: