Using Parameters

A parameter can be inserted into any text attribute. For example, the following is a where expression which accept records whose field EntryDate is between two dates:

        (EntryDate >= ${from_date}) and (EntryDate < ${to_date})
      

The text ${from_date} will be replaced by whatever the value of from_date is. The value is supplied either by the user via a parameter dialog, or via a script. Additionally, the form ${name:defval} may be used; in this case, if name is not otherwise defined, then defval will be used. This is useful in where expressions like:

        Company like '${Company:%}'
      

In this case, a pattern can be supplied which filters by company name; if no pattern is supplied then % matches all companies.

An example in the dialog below, which is accessed by going to Block Properties and clicking the Query button.