Question

I’m using MS SQL Server but welcome comparitive solutions from other databases.

This is the basic form of my query. It returns the number of calls per day from the ‘incidentsm1’ table:

SELECT    COUNT(*) AS 'Calls',   MAX(open_time),   open_day FROM    ( SELECT  incident_id,  opened_by,  open_time - (9.0/24) AS open_time,  DATEPART(dd, (open_time-(9.0/24))) AS open_day    FROM incidentsm1     WHERE   DATEDIFF(DAY, open_time-(9.0/24), GETDATE())< 7    ) inc1 GROUP BY open_day 

This data is used to draw a bar graph, but if there were no calls on a given day of the week, there is no result row and thus no bar, and the user is like, ‘why does the graph only have six days and skip from Saturday to Monday?’

Somehow I need to UNION ALL with a blank row from each day or something like that, but I can’t figure it out.

I am constrained to what I can do with one SQL statement and I have readonly access so I can’t create a temporary table or anything.

Answer 1

How about something like this?

SELECT    COUNT(incident_id) AS 'Calls',   MAX(open_time),   days.open_day FROM (   select datepart(dd,dateadd(day,-6,getdate())) as open_day union   select datepart(dd,dateadd(day,-5,getdate())) as open_day union   select datepart(dd,dateadd(day,-4,getdate())) as open_day union   select datepart(dd,dateadd(day,-3,getdate())) as open_day union   select datepart(dd,dateadd(day,-2,getdate())) as open_day union   select datepart(dd,dateadd(day,-1,getdate())) as open_day union   select datepart(dd,dateadd(day, 0,getdate())) as open_day  ) days left join  (  SELECT    incident_id,    opened_by,    open_time - (9.0/24) AS open_time,    DATEPART(dd, (open_time-(9.0/24))) AS open_day  FROM incidentsm1   WHERE DATEDIFF(DAY, open_time-(9.0/24), GETDATE()) < 7 ) inc1 ON days.open_day = incidents.open_day GROUP BY days.open_day 

I’ve only tested it on a simplified table schema, but I think it should work. You might need to tinker with the dateadd stuff..