我的SQL查询有什么问题？ （无法获得理想的输出/输出）

Question

I want my query to return number of users registered in a particular day between current date and 7 days before. Instead of days, in date-time format it shows it in integer format. Example, for date 20/12/2012 its showing as 0, 21/12/2012 as 1 and so on

My Query:

select date(update_timestamp) between date_sub(sysdate(), interval 7 day) and sysdate()  as date, count(*) users 
from registered 
group by date(update_timestamp)

Desired Output

DATE       | USERS
20/12/2012 | 5
21/12/2012 | 6

Output i'm getting

DATE  | USERS
    0 | 5
    1 | 6

What is wrong with my sql query? Also, i need to know the alternate way of fetching last 7 days data

Answer 1

I think you want a WHERE clause:

select date(update_timestamp) Date, count(*) users 
from registered 
where date(update_timestamp) between date_sub(sysdate(), interval 7 day) and sysdate()
group by date(update_timestamp)

Answer 2

You have put the condition in the select statement, so it will be evaluated and returned, instead of limiting the result. Put the condition in the where statement:

select date(update_timestamp) as date, count(*) users
from registered
where date(update_timestamp) between date_sub(sysdate(), interval 7 day) and sysdate()
group by date(update_timestamp)

---

To get all the dates in the interval even if there are no users, you need to join in another source of data:

select date_sub(sysdate(), interval d.offset day) date, count(r.update_timestamp) users
from registered r
inner join (
  select 0 as offset union all
  select 1 union all
  select 2 union all
  select 3 union all
  select 4 union all
  select 5 union all
  select 6 union all
  select 7
) d on date(r.update_timestamp) = date_sub(sysdate(), interval d.offset day)
group by date_sub(sysdate(), interval d.offset day)

Answer 3

try this query ::

where clause is the filtering part, For the date type logic you should use your current day - 7 days logic in that part of the query.

select date(update_timestamp) ,count(*) users 
from registered 
where date(update_timestamp) 
between 
date_sub(sysdate(), interval 7 day) and sysdate()  
group by date(update_timestamp)