SQL日期检查在设定的天数内

Question

Im trying to find out how many clients viewed a property within 14 days of May 20, 2004, either before or after. Not really sure at all how to go about this.

Im assuming i need to group it and use a having?

EDIT: I am using oracle now

select count(*)
from VIEWING
WHERE CLAUSE?

Answer 1

For a one time query with that specific date,

select count(*) clients
from yourtable
where yourdatefield >= {d'2004-05-06'}
and yourdatefield < {d'2004-06-08'}

You might want to consult a calendar to see if those dates are correct.

Answer 2

Edit #1, since you are using Oracle, you can use:

select count(*) TotalClients
from yourtable
where dt >= (to_date('2004-05-20', 'yyyy-mm-dd') - INTERVAL '14' DAY)
  and dt <= (to_date('2004-05-20', 'yyyy-mm-dd') + INTERVAL '14' DAY)

See SQL Fiddle with Demo

Based on some of your previous questions you were using MySQL.

If you are using MySQL then you can use the DATE_ADD() function to get the date range and then use count(*) to return all records from those dates:

 
 
 
 
  
  
  select count(*) TotalClients from yourtable where dt >= date_add(str_to_date('2004-05-20', '%Y-%m-%d'), INTERVAL -14 day) and dt <= date_add(str_to_date('2004-05-20', '%Y-%m-%d'), INTERVAL 14 day)