These types of validations use the PL/SQL
language to determine the outcome of the validation. Take note
that while using the validation creation wizard to create this
type of validation, text will appear below the main region on
the Validation Method page as shown in Figure 12.2. Clicking on
the links of the text in bold reveals the syntax examples.
These are valuable and should be used when necessary. The
following is a brief summary of help not found in the HTML DB
: Same at
the SQL Expression above.
Used to raise an application error.
: A PL/SQL function returning the TRUE
or FALSE validation status.
: This is useful if error messages
are stored in a database table because the text could be queried
and returned from the function. If this method is used, a value
for the Error Message is not needed even though it still shows
as a mandatory field.