Single-Record Constraints

The scope of a single-record constraint is restricted to the columns of one table. In the constraint you either use a SELECT or UPDATE statement.

EXAMPLE:

Consider the business rule: "A reservation can only be canceled after the reservation is booked." This rule is implemented by a restrictive single-record constraint:

SELECT '' violation

FROM reservation

WHERE cancel_date < book_date

The Rules Engine validates single-record constraints at record validation time, when the record is stored. Corrective single-record constraints are validated before restrictive single-record constraints.