I assume your [Expense Log] table has a column that lists the category to which each expense belongs? If that column is a single or multiple select field, just change it to a Link to Another Record field pointing to your [Summary] table. Each category will now have a row in your [Summary].
In [Summary] add a new Rollup field that uses the SUM(values)
aggregation for whatever field in [Expense Log] contains the cost of that expense.
I assume your [Expense Log] table has a column that lists the category to which each expense belongs? If that column is a single or multiple select field, just change it to a Link to Another Record field pointing to your [Summary] table. Each category will now have a row in your [Summary].
In [Summary] add a new Rollup field that uses the SUM(values)
aggregation for whatever field in [Expense Log] contains the cost of that expense.
thank you so much I will try figure that out.