mysql - ERROR 1064 (42000) over partition by 语法中的数据库错误

Question

mysql> select * from FinalTable;
+------+-------+-------+---------------------+
| id   | name  | state | timestamp           |
+------+-------+-------+---------------------+
|   12 | name1 | TX    | 2020-01-25 11:29:36 |
|   14 | name3 | CA    | 2020-01-25 11:29:36 |
|   14 | name3 | TX    | 2020-01-25 11:29:36 |
|   12 | name1 | CA   | 2020-01-25 11:29:36 |
|   13 | name2 | TA   | 2020-01-25 11:29:36 |
|   14 | name3 |  CA   | 2020-01-25 11:29:36 |
+------+-------+-------+---------------------+

我正在查看输出查询，其响应如下:

I2 name1 TX 2020-01-25 11:29:36  CA 2020-01-25 11:29:36

当我运行查询时，

select id,name,state,timestamp,
lead(state,1) over (partition by id order by timestamp asc) out_state,
lead(timestamp,1) over (partition by id order by timestamp asc) out_timestamp
from FinalTable

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '(partition by id order by timestamp asc) out_state,
lead(timestamp,1) over (part' at line 2

还可以在数据库中创建高达毫秒而不是秒的时间戳吗？我正在使用 CURRENT_TIMESTAMP。

Answer 1

窗口函数(例如lead())仅在MySQL 8.0中添加，因此它们在5.7版本中不可用。您可以使用自连接来模拟 lead() ，如下所示:

select t.*, tlead.state, tlead.timestamp
from FinalTable t
left join FinalTable tlead 
    on tlead .id = t.id
    and tlead.timestamp = (
        select min(t1.timestamp) 
        from FinalTable t1 
        where t1.id = t.id and t1.timestamp > t.timestamp
    )

旁注:要使此方法正常工作，您需要相同 id 的后续记录具有不同的 timestamp - 示例数据中的情况并非如此您所展示的，其中所有时间戳都是相同的(我认为这是您的示例数据中的拼写错误)。