Question

I have a table that contains information for player’s steps taken for any given day, I want to get the 3 highest totals from the database, when the day before the day of the high total has a value added to it for that player. Since some players are not logging everyday, but rather lumping multiple days into one update.

Data Structure:

|---------------------------------------------------------------|
| id | player_id | steps | date       | submitted               |
|----|-----------|-------|------------|-------------------------|
| 1  | 16        | 5718  | 2012-09-06 | 2012-09-10 08:31:35.000 |
| 2  | 16        | 9837  | 2012-09-07 | 2012-09-10 08:31:17.000 |
| 3  | 16        | 10432 | 2012-09-09 | 2012-09-10 08:30:54.000 |
| 4  | 30        | 3973  | 2012-09-07 | 2012-09-10 09:34:42.000 |
| 5  | 30        | 7104  | 2012-09-08 | 2012-09-10 09:35:05.000 |
| 6  | 30        | 10916 | 2012-09-09 | 2012-09-10 09:35:29.000 |
| 7  | 9         | 6437  | 2012-09-07 | 2012-09-10 09:39:15.000 |
| 8  | 9         | 9032  | 2012-09-08 | 2012-09-10 09:40:02.000 |
|---------------------------------------------------------------|

So what I want to return are the rows:

|---------------------------------------------------------------|
| 6  | 30        | 10916 | 2012-09-09 | 2012-09-10 09:35:29.000 |
| 2  | 16        | 9837  | 2012-09-07 | 2012-09-10 08:31:17.000 |
| 8  | 9         | 9032  | 2012-09-08 | 2012-09-10 09:40:02.000 |
|---------------------------------------------------------------|

My query is currently:

SELECT TOP 3 p.name,
             player_id,
             steps,
             date
FROM   steppers_step_log
       JOIN steppers_players P
         ON player_id = P.id
ORDER  BY steps DESC 

Which does not take into account whether there is an entry for the date prior on the top 3 from steps, which with my query in its current form will return 10432, 10916, and 9837 as the top steps.

I am having trouble working out how to do the WHERE command to make sure that the previous day has an entry for that player_id and would appreciate any help in getting it working.

Answer 1

Something like this?

SELECT TOP 3 p.name,
             player_id,
             steps,
             date
FROM   steppers_step_log
       JOIN steppers_players P
         ON player_id = P.id
WHERE EXISTS
(
   SELECT 1 FROM steppers_step_log ssp
   WHERE ssp.player_id = P.id
   AND date = DATEADD(day, -1, steppers_step_log.date)
)
ORDER  BY steps DESC 

DATEADD (Transact-SQL)