When a DataWindow data expression is evaluated
Expressions that refer to DataWindow data are not verified until
execution of your application.
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 or change 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,
an error will occur at runtime.
You can handle the error by surrounding the expression in a
try-catch block and catching any DWRuntimeErrors, or by writing a
script for the DataWindow control’s Error event.