Access Database top query problems [go]

If order by is used after the top query statement, and the order by field contains duplicate values, this top will become invalid.
All records are returned.
For example, select top 5 from news order by createdate
If there are duplicate values in createdate, all records will be displayed, and this top function is invalid. However, if no duplicate value exists in createdate, the top function is still valid. Therefore, when using the top function in access, pay attention to whether the order by field has duplicate values. For example, if createdate is "year-month-day hour: minute: Second, that's basically not a problem. But for the sake of insurance, we can also use the "add primary key" method: Select top 5 from news order by createdate DESC, Id DESC
This problem can be prevented by using the primary key as a guarantee that "It cannot be repeated ".