SQL group by date, but get dates w/o records too

Question

Is there an easy way to do a GROUP BY DATE(timestamp) that includes all days in a period of time, regardless of whether there are any records associated with th

Answer 1

In a data warehouse, the method taken is to create a table that contains all dates and create a foreign key between your data and the date table. I'm not saying that this is the best way to go in your case, just that it is the best practice in cases where large amounts of data need to be rolled up in numerous ways for reporting purposes.

If you are using a reporting layer over SQL Server, you could just write some logic to insert the missing dates within the range of interest after the data returns and before rendering your report.

If you are creating your reports directly from SQL Server and you do not already have a data warehouse and there isn't the time or need to create one right now, I would create a date table and join to it. The formatting necessary to do the join and get the output you want may be a bit wonky, but it will get the job done.