Adds a condition, known as a constraint, that affects adding or
    modifying data in a database table (record). Supported constraint
    types are NOT NULL, PRIMARY KEY, FOREIGN KEY, UNIQUE, and CHECK.

    Each constraint can be named and supplied with evaluation
    attributes DEFERRABLE or NOT DEFERRABLE. The default evaluation
    time for constraints in CDO is NOT DEFERRABLE (the constraint
    is evaluated at statement time). For more information, see the
    DEFINE RECORD_Constraint command.