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,其给出的响应为:
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DB中创建最多毫秒而不是秒的时间戳吗?我正在使用CURRENT_TIMESTAMP。
Window函数(例如lead()
)仅在MySQL 8.0中添加,因此在5.7版中不可用。您可以像这样通过自连接来模拟lead()
:
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:为使此方法正常工作,您需要相同id
的后续记录具有不同的timestamp
-在您显示的样本数据中情况并非如此,因为所有时间戳都相同(我认为这是您的示例数据中的错字)。