Report errors returned poor quality or null

Im trying to create a report this is the first report i have ever done and i keep getting errors. I am attaching pictures. I keep getting this error WARN: Default value expression for parameter “StartString” returned poor quality: [null, Error_ExpressionEval(“Date argument to dateFormat function cannot be null”), Wed Jul 07 21:22:10 EDT 2021 (1625707330570)] and WARN: Error executing query parameter expression " {StartString}" not sure how to fix this or whats wrong

Several thoughts:

  1. Remove the leading space from the Parameter 1 and Parameter 2 boxes. This probably isn’t your problem, but housekeeping is always a good start for troubleshooting.
  2. To fix the error that’s being thrown I think we’ll need to see the expression for StartString. It looks like the expression isn’t formatted correctly. (Doesn’t have enough arguments?)
  3. I don’t think you need to convert the dates to strings to use in your SELECT query. You should be able to pass the Date objects in directly and the JDBC driver will do the magic for you. The one reason this might not be true is if you’re changing the dates in your StartString/EndString logic, but we’ll be able to see that when you post that logic.

Here is the documentation for dateFormat. It may be useful. dateFormat

Here is the code for the startstring and endstring parameters
dateFormat({StartDate}, ‘yyyy-MM-dd HH:mm:ss’)
dateFormat({EndDate}, ‘yyyy-MM-dd HH:mm:ss’)

What is the code for the StartDate paramter?

Please use code formatting when pasting code to the forums. It makes it much easier to read. You can do this by highlighting the section of text and pushing the Preformatted Text Button. It looks like this. </>

What’s the code on the StartDate parameter?

dateArithmetic(now(), -8, "hr")