Constraint messages

In restrictive constraints it is customary to specify a message. The runtime message is presented as a message of type Error, because it occurs at a time when processing is blocked.

In corrective constraints it is not customary to specify a message. If you do specify a message, at runtime it is presented as a message of type Warning.

You can change a restrictive constraint into a warning constraint or even into a constraint that only gives an informative message (a message of type Information).

USoft Definer has a Language module. This allows you to localise your application. An important part of this localisation is that you can optionally specify message translations, so that the runtime user can automatically get the message in her own language.

You can have variable elements in your constraint messages. This allows you to produce error messages and warning messages that are more informative to your end user.

Variable elements in constraint messages are marked by angle brackets (<>). These variables can refer to:

•Values of columns used in the constraint.

•Values of alias names for columns used in the constraint.

•Old values of columns used in the constraint.

•Parameter values of methods used in the constraint.

•Meta information of columns and tables, like table names, object names, and prompts.

Examples

Variable constraint messages: Example 1

Variable constraint messages: Example 2

Variable constraint messages: Example 3

Variable constraint messages: Example 4

Variable constraint messages: Example 5

Variable constraint messages: Example 6

Supported constraint variables