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Vyhodnocovací funkce
Check_Primary_Key
(ER Model)


Vytvořeno: 07-06-1999 15:45:35
Poslední změna: 12-03-2002 13:33:26

Checks the existence of a Primary key for the Entity-Type.

Modul

Module: ER Model

Zdrojový kód:

PROCEDURE Check_Primary_Key(Entity$, BYREF pkey!)
BEGIN

    FOR Entity WHERE Entity.Name = Entity$ DO
        // check if Primary key contains Attribtues
        FOREACH Identifierattribute WHERE Identifierattribute.Identifier = Entity.Primaryidentifier AND
                                          Identifierattribute.Entity = Entity.Name DO
                 pkey! = TRUE;
                 BREAK;
        END
        IF NOT pkey! THEN
            // check if Primary key contains Relationshiptypes
            FOREACH Identifiererconnection WHERE Identifiererconnection.Identifier = Entity.Primaryidentifier AND
                                                 Identifiererconnection.Entity = Entity.Name DO
                     pkey! = TRUE;
                     BREAK;
            END
        END
        IF NOT pkey! THEN
            // if Entity-Type is Sub Entity-Type check Primary key of Super Entity-Type
            FOREACH Erconnection WHERE Erconnection.Entity = Entity.Name AND
                                        Erconnection.Cardinality = "sz" DO
                FOR Rship WHERE Rship.Id = Erconnection.Rship DO
                    FOREACH Erconnection WHERE Erconnection.Rship = Rship.Id AND
                                                Erconnection.Cardinality = "ge" DO
                        CALL Check_Primary_Key(Erconnection.Entity, pkey!);
                    END
                END
            END
        
        END
    END

END


Generováno: 16.10.2003 7:41 Systém: C:\Documents and Settings\hajsman\Dokumenty\Vyuka\Irs2\Projekt case40\Projekt03.csf Generováno systémem case/4/0
Vygeneroval: Administrator Soubor: C:\Documents and Settings\hajsman\Dokumenty\Vyuka\Irs2\Projekt case40\html\2086718.htm (C) microTOOL GmbH 2002