Association - Generation specific to Oracle

Referential constraints

Referential constraints are mapped by the following instructions:

SQL89 CONSTRAINT ... FOREIGN KEY ... REFERENCES.

Parameterization

Referential constraint names can be parameterized using the SetForeignKeysNames J method which simply has to be redefined under a UML Profile. The method’s parameters are as follows:

The ... parameter	represents ...
ComposedClassName	the name of the composed class
fkDest	the destination "foreign key"
fkOrigin	the origin "foreign key"

SetForeign-KeysNames method

// Default value for Oracle.

AssociationEnd:default#external#Code#RDB#DDL#Oracle#

SetForeignKeysNames

(in String ComposedClassName,

inout String fkOrigin,

inout String fkDest)

{

String fkO;

String fkD;

fkO = SetTableName(ComposedClassName);

fkD = SetTableName(ComposedClassName);

fkO.concat("_OFK");

fkD.concat("_DFK");

fkOrigin = fkO;

fkDest = fkD;

}

// method SetForeignKeysNames

Mulitplicity constraints

The generation of tables for Oracle V8 uses triggers to map multiplicity constraints in associations.

Multiplicity constraints are checked after insertion by a trigger named TI_name of the table. However, Oracle cannot be used to generate an AFTER DELETE type trigger, able to manage minimum multiplicities during a deletion.

We will generate a multiplicity test through association orientation if the association is mutual with m-n multiplicity.

Example of multiplicity constraints

DDL generated for an association with the 0-5 multiplicity:

CREATE TRIGGER TI_role2_of_class

BEFORE INSERT

ON role2_of_class

FOR EACH ROW

DECLARE

dummy INTEGER;

BEGIN

SELECT COUNT(*)

INTO dummy

FROM role2_of_class

WHERE clef = :new.clef;

IF NOT(dummy < 5)

THEN raise_application_error(-20501,

'role2_of_class : May not insert element');

END IF;

END ;

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