I have a Google spreadsheet for expenses: one column for the YYYY-MM-DD date of the expense, one column for the category, and one column for the amount. This sheet has thousands of rows. The goal is a pivot table with MM-YYYY in the column, summing amounts by the month/year.
Usually, that's easy. I create the pivot table with the ungrouped variable in the column, and then right click and create a pivot table group. However, when I create a pivot table with the date as the column of the table, Google Sheets says
This pivot table is trying to produce too many columns. Make it smaller by adjusting the column breakouts or filtering the source data.
There isn't a column to right click on to create the group because Google Sheets couldn't produce any of the columns (see screenshot)
How do I create a pivot table group here? Is the only to create another column in the sheet with the raw data (I'd prefer not to do this because that sheet is an output from another program) that does the grouping with a formula?