我有一个带有日期戳的交易表。我想添加一列来对记录进行编号，但它们必须每天重新启动。这可能吗？
示例:
+------------------+--------------+
| Date | Data |
+------------------+--------------+
| 19-10-2017 10:18 | Transaction1 |
| 19-10-2017 12:18 | Transaction2 |
| 19-10-2017 13:23 | Transaction3 |
| 20-10-2017 11:18 | Transaction4 |
| 20-10-2017 14:18 | Transaction5 |
| 21-10-2017 09:18 | Transaction6 |
| 21-10-2017 10:18 | Transaction7 |
| 21-10-2017 11:18 | Transaction8 |
| 21-10-2017 12:18 | Transaction9 |
+------------------+---------+----+
我想要这个:
+------+------------------+--------------+
| Nr | Date | Data |
+------+------------------+--------------+
| 1 | 19-10-2017 10:18 | Transaction1 |
| 2 | 19-10-2017 12:18 | Transaction2 |
| 3 | 19-10-2017 13:23 | Transaction3 |
| 1 | 20-10-2017 11:18 | Transaction4 |
| 2 | 20-10-2017 14:18 | Transaction5 |
| 1 | 21-10-2017 09:18 | Transaction6 |
| 2 | 21-10-2017 10:18 | Transaction7 |
| 3 | 21-10-2017 11:18 | Transaction8 |
| 4 | 21-10-2017 12:18 | Transaction9 |
+------+------------------+--------------+
最佳答案
您可以尝试以下解决方案:
SELECT
@row_number:=CASE WHEN DATE(@date_value)=DATE(`Date`) THEN @row_number + 1 ELSE 1 END AS row_number,
@date_value:=`Date` AS `Date`
FROM test, (SELECT @row_number:=0, @date_value:=DATE(NULL)) AS t
ORDER BY `Date`, row_number
关于mysql - 将每天递增的数字添加到表中，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/46988647/