How to extend the query to add 0 in the cell when no activity is performed

Question

I have the following query, it is working fine to show the cricket time played per day. All I need is to show 0 when no cricket is played. At the moment it is skipping those

Answer 1

This is a long query but should give you what you need.. It will also work for multiple activities.

;
    WITH    CTE
            AS ( SELECT   email ,
                        last_update ,
                        activity ,
                        starttime ,
                        endtime ,
                        duration AS [Totaltime]
                FROM     users
                WHERE    activity = 'cricket'
                        AND email = 'abc'
                GROUP BY email ,
                        activity ,
                        duration ,
                        starttime ,
                        endtime ,
                        last_update
                ),
        cteSummary
            AS ( SELECT   activity ,
                        CAST(starttime AS DATE) AS date ,
                        SUM(DATEDIFF(second, starttime, endtime)) / 60.0 AS TimePerDay
                FROM     cte
                WHERE    starttime >= DATEADD(day, -15, last_update)
                GROUP BY activity ,
                        CAST(starttime AS DATE)
                ),
        cteDateRange
            AS ( SELECT   activity ,
                        MIN(date) AS MinDate ,
                        MAX(date) AS MaxDate
                FROM     cteSummary
                GROUP BY activity
                ),
        cteDateRecur
            AS ( SELECT   activity ,
                        CalDate = CONVERT(DATE, MinDate) ,
                        MaxDate
                FROM     cteDateRange
                UNION ALL
                SELECT   activity ,
                        CalDate = DATEADD(DAY, 1, c.CalDate) ,
                       MaxDate
                FROM     cteDateRecur c
                WHERE    c.CalDate < c.MaxDate
                )
    SELECT  d.activity ,
            d.CalDate AS date ,
            ISNULL(s.TimePerDay, 0) AS TimePerDay
    FROM    cteDateRecur d
            LEFT JOIN cteSummary s ON d.CalDate = s.date
    OPTION  ( MAXRECURSION 0 )

Answer 2

You need a list of dates. The easiest way -- if you have data on each date, but just not for the where conditions -- is to use conditional aggregation:

Select activity, cast(starttime as date) as date,
       SUM(case when activity = 'cricket' and email = 'abc'
                then datediff(second, starttime, endtime))/60.0
                else 0
           end) as TimePerDay
from users
where starttime >= dateadd(day, -15, last_update)
group by activity, cast(starttime as date);

Otherwise, if the dates are not in the table, then you need a list of dates. This can come from:

• A calendar table.
• A recursive CTE.
• An explicit list in the query.

Answer 3

Try this. You can generate the missing dates in a union by using the existing CTE as a basis for Row_Number()

;WITH CTE AS (
SELECT email, last_update, activity, starttime, endtime, duration as [Totaltime] from users 
WHERE activity='cricket' and email='abc'
GROUP BY email, activity, duration, starttime, endtime, last_update
)
Select activity, cast(starttime as date) as date,
SUM(datediff(second, starttime, endtime))/60.0 as TimePerDay
from cte
where starttime >= dateadd(day, -15, last_update)
group by activity, cast(starttime as date)
UNION ALL
Select 'cricket' activity, everyday.[date], 0
FROM 
(
    select top 1000 dateadd(day,row_number() OVER (order by starttime),(select cast(min(starttime) as date) from CTE)) [date]
    from CTE
) everyday
WHERE everyday.[date] NOT IN (SELECT cast(starttime as date) FROM CTE)
AND everyday.[date] < (SELECT cast(max(starttime) as date) from CTE)
ORDER BY date

Answer 4

First You have to generate the Date series with a query like this:

-- Generate 15 past days name from now
set @n:=date(now() + interval 1 day);
select (select @n:= @n - interval 1 day) day_series from users  limit 15;

and then join select with date_series. for null values you can use COALESCE:

SELECT q2.day_series as days , COALESCE(TimePerDay, 0) as TPD from Your_select q1
right join (
    -- select date_series
) as q2
on q1.Timestamp = q2.day_series and .... 

--- final Query based on my understanding from 1st query

set @n:=date(now() + interval 1 day);
SELECT activity
,cast(starttime AS DATE) AS q1_DATE
,COALESCE(SUM(datediff(second, starttime, endtime)) / 60.0, 0) AS TimePerDay
FROM (
    SELECT email
        ,last_update
        ,activity
        ,starttime
        ,endtime
        ,duration AS Totaltime
    FROM users
    WHERE activity = 'cricket'
        AND email = 'abc'
    GROUP BY email
        ,activity
        ,duration
        ,starttime
        ,endtime
        ,last_update
    ) q1
RIGHT JOIN (
    SELECT (
            SELECT @n: = @n - interval 1 day
            ) day_series
    FROM users limit 15
    ) q2 ON q1.q1_DATE = q2.day_series
WHERE starttime >= dateadd(day, - 15, last_update)
GROUP BY activity
    ,cast(starttime AS DATE);

Answer 5

you could try this also :- (this could only for one particular activity)

Set Nocount On;

Declare  @MinDate   Date
        ,@MaxDate   Date

Declare @test Table
(
     activity       Varchar(100)
    ,date           Date
    ,TimePerDay     Decimal(5,2)
)

Declare @result Table
(
     activity       Varchar(100)
    ,date           Date
    ,TimePerDay     Decimal(5,2) Default 0
)

;WITH CTE AS 
(
    SELECT   email
            ,last_update
            ,activity
            ,starttime
            ,endtime
            ,duration As Totaltime 
    From    users With (Nolock)
    WHERE   activity ='cricket' 
            And email = 'abc'
    GROUP BY email
            ,activity
            ,duration
            ,starttime
            ,endtime
            ,last_update
)

Insert Into @test(activity,date,TimePerDay)
Select   activity
        ,Cast(starttime as date) As date
        ,SUM(datediff(second, starttime, endtime))/60.0 As TimePerDay
From    cte With (Nolock)
where   starttime >= dateadd(day, -15, last_update)
group by activity
        ,cast(starttime as date)

Select   @MinDate = Min(Date)
        ,@MaxDate = Max(Date)
From    @test

;With AllDates As
(
    Select   @MinDate As xDate
    From    @test As t1
    Where   t1.date = @MinDate

    Union All

    Select  Dateadd(Day, 1, xDate)
    From    AllDates As ad
    Where   ad.xDate < @MaxDate
)

One way is :- (left join)

Select  'cricket' As activity
        ,ad.xDate
        ,Isnull(t.TimePerDay,0) As TimePerDay
From    AllDates As ad With (Nolock)
        Left Join @test As t On ad.xDate = t.date

another way is :- (insert with all dates and update)

    Insert Into @result(activity,date)
Select  'cricket'
        ,ad.xDate
From    AllDates As ad With (Nolock)

Update  t
Set     t.TimePerDay = t1.TimePerDay
From    @result As t
        Join @test As t1 On t.date = t1.date

Select  *
From    @result As r

output

Update

Declare  @MinDate   Date
        ,@MaxDate   Date

Select   @MaxDate = Getdate()
        ,@MinDate = Dateadd(Day, -14, @MaxDate)

;With AllDates As
(
    Select   @MinDate As xDate

    Union All

    Select  Dateadd(Day, 1, xDate)
    From    AllDates As ad
    Where   ad.xDate < @MaxDate
)

Select   @activity As activity                      ---- @activity (your stored procedure parameter)
        ,ad.xDate
        ,Isnull(t.TimePerDay,0) As TimePerDay
From    AllDates As ad With (Nolock)
        Left Join @test As t On ad.xDate = t.date

Answer 6

AS PREPARATION, you need to generate a list of dates. There are multiple ways for that. One is a recursive CTE. For example, this one creates a list of the last 15 days:

with datelist ([date]) as 
(
    select dateadd(dd, -15, cast(getdate() as date)) as [date] -- 15 days back
    union all
    select dateadd(dd, 1, [date]) from datelist where dateadd(dd, 1, [date]) <= getdate()
)
select * from datelist option (maxrecursion 400)

FOR THE FINAL SOLUTION, you now need to create a LEFT JOIN between the datelist and with a subquery with your user table. An overall solution for your question therefore goes as follows.

I have also put everything together in a SQLFiddle: http://sqlfiddle.com/#!3/36510/1

with datelist ([date]) as 
(
    select dateadd(dd, -15, cast(getdate() as date)) as [date] -- 15 days back
    union all
    select dateadd(dd, 1, [date]) from datelist where dateadd(dd, 1, [date]) <= getdate()
)
select 'cricket' as activity, 
       d.[date],
       coalesce(SUM(datediff(second, u.starttime, u.endtime)/60.0), 0)
            as TimePerDay      
from datelist d
     left join 
     (
          select [starttime], [endtime], cast(starttime as date) as [date]
          from [users]  
          where activity='cricket' and email='abc'
     ) u
     on d.[date] = u.[date]
group by d.[date]
option (maxrecursion 400)

So this query will give you the table for the cricket activity of the last 15 days of one specific user.