It would be a huge improvement to include new functions to the expression editor or the ability to add custom functions to this editor. Specifically:
- a function to count distinct items in a field
- a date constructor ( so a custom date could be constructed using the day() month() year() items ie. date(month(today()),day(today(),year()) so that we could use dateadd() to generate very specific date ranges.
- Days in year (returns the number of days in the current year)
- A running sum aggregate
- Concatenate for combining strings and results
- Financial Functions (Depreciation, NPV, standard excel and report finance functions.
- Database and data type functions... Another large list of useful functions for data qualifying and filtering etc.
- More text functions like extract from str, money, contains etc
Being able to add C# functions or something in a similar language would expand reporting functionality immensely