--
-- Creates logical constraints
--   A logical constraint is one that cannot ordinarily be made as a database constraint (e.g. 
--   mandatory associations implemented in > 1 table.) This sort of construct cannot be 
--   done using a foreign key and hence must be validated by a deferred check on closing
--   a transaction. In order for a deferred check to work, an assertion must be prepared.
--   It is the responsibility of this package to create these assertions.

create or replace package jrm_deferred_check is

-- PRE : product_name is a valid name in the RM meta-model
-- POST: all logical constraints are identified and assertions created. The instance data
--       logical constraint code is created and made into an expression.
procedure createLogicalConstraints( product_name VARCHAR2 );

-- function getExpression
--
-- The expression is the 'call-back' body used by deferred_checks. This will (at runtime)
-- provide the logic to the constraints identified in identifyLogicalConstraints
-- PRE:  expID is a valid expression defined against an assertion
--       lineId is the line number of the sql part of the expression
-- POST: the sql part for this expression id and line number is returned
function getExpression( expId IN NUMBER , lineId IN NUMBER) return varchar2;

-- PRE:  expId is a valid expression defined against an assertion
-- POST: the number of lines of sql used in the 'call-back'
function getExpressionSize( expId IN NUMBER) return number;

end jrm_deferred_check;
/