Use of Date Strings in Datawindow Filters

Question

In a number of datawindows in my application, users have access to a free-form text box where they can enter any filter string they like. Frequently, they will successfully use a search term like: date(last_updated_date) = 2010-10-22

I'm trying to update some documentation and have been asked to address this syntax in particular. So my question is this: how does PowerBuilder know that "2010-10-22" is a date and what are the rules for including date literals like this one without specific conversion? Is it based upon the fact that the left-hand value is clearly a date datatype or is it based upon the particular date format used in "2010-10-22" or both? Just to be clear: this syntax woks properly.

Answer 1

It is definitely the format for literal dates (without quotes), and there is no need to compare with the left side of the comparison to handle it as a date.

In the "Standard dataypes" section, the documentation states for the type "Date":

The date, including the full year (1000 to 3000), the number of the month (01 to 12), and the day (01 to 31). Using literals To assign a literal value, separate the year, month, and day with hyphens. For example:

2001-12-25 // December 25, 2001

2003-02-06 // February 6, 2003

Answer 2

All what Seki said about the literals it’s true. If you want/have to use strings however, the format „yyyy-mm-dd” is the one that will always work when comparing with/assigning to a date type variable. It’s considered the standard for date format.

If a different string format is used as a date, for example „25-12-2012”, PB uses Windows regional settings to convert it. If conversion fails you’ll get 1900-01-01.

You can also check PB help „Date PowerScript function/Convert a string to a date”.