知道如何从今天的日期检索属于前一周的日期吗？

Question

I have a table "dates" with ids and dates: (the dates are in timestamp)

id start_date
1  2020-11-23 11:00:00
2  2020-11-23 12:00:00
3  2020-11-15 10:00:00
4  2020-11-24 09:00:00
5  2020-11-11 09:00:00
6  2020-11-24 13:00:00
7  2020-11-25 15:00:00

the code should return ids:

id
 1
 2
 4
 6
 7

i tried the following:

select id
from dates
where dates.start_date > DATE_SUB(DATE(NOW()), INTERVAL DAYOFWEEK(NOW())+6 DAY) 
AND dates.start_date <= DATE_SUB(DATE(NOW()), INTERVAL DAYOFWEEK(NOW())-1 DAY)

but it didn't seem to work. I'm having a syntax error:

ERROR: syntax error at or near "DAYOFWEEK"

Consider today's date: 2020-11-26 I'm also using PostgreSQL!

Answer 1

You seem to want:

select id
from t
where t.start_date > current_date - interval '7 day';

Or, perhaps -- depending on how you define "week":

where t.start_date >= date_trunc('week', current_date) - interval '7 day' and
      t.start_date < date_trunc('week', current_date)