MySQL WHERE 条件从小时开始选择所有记录

Question

WHERE timestamp >= NOW() - INTERVAL 1 HOUR

The above query works fine to get data that belongs to last 1 HOUR. Let's say I run the query at 2020-10-15 18:08:00. It will give me all the records between the below time period.

2020-10-15 17:08:00 - 2020-10-15 18:08:00

I have been trying to create a mysql query to get data from the beginning of the hour. Let's again say I ran the query at 2020-10-15 18:08:00. I need a query to get me the results belonging the below time period.

2020-10-15 18:00:00 - 2020-10-15 18:08:00

I would appreciate some feedback on this.

Answer 1

In many databases (as Postgres for example), you can do this with date_trunc() , or the-like (in Oracle: trunc() ).

Unfortunately MySQL does not implement this function - however it is flexible enough to understand dates as strings. I like to use date_format for this:

where timestamp >= date_format(now(), '%Y-%m-%d %H:00:00')