The relation attribute @ONNOVALUEis used to define an error if no value can be selected from a Telitab data set.

Syntax

Place @ONNOVALUE:ParameterName,MessageCaption[,Action] in the data slot of the relation

Arguments

ParameterName defines the parameter containing the error message. You can also directly type the message between quotes.
MessageCaption is the caption of the message box presenting the error.
Action is optional, when no action is given, Quaestor will stop. When continue is written, Quaestor will continue after the message.

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