When
a DataWindow property expression is evaluated in PowerBuilder
In PowerBuilder, expressions that refer to DataWindow object
properties and data are not verified until your application runs.
No compiler checking
When your script is compiled, PowerBuilder does not verify the
parameters of the expression that follow the Object property. Your
application can select the DataWindow object in a DataWindow control at
runtime without invalidating the compiled script.
Potential execution errors
If the datatype of the expression is not compatible with how the
expression is used, or if the specified rows or columns do not exist,
then an error will occur at runtime.
You can handle the error by surrounding the expression in a
try-catch block or by writing a script for the DataWindow Error
event.