MySQL GROUP BY and Fill Empty Rows

Question

I\'m sure this has been answered before, but I can\'t find it in the detail that I need.

For an analytics system I need to be able to group rows and return them on a

Answer 1

This is typically done in data warehouses by having a date dimension that has a list of all possible dates. You do an OUTER JOIN to the date dimension and COALESCE the null values to 0.