Handling Set-relations

Modeling Services > Relations > Set-relations > Handling Set-relations

The class templates IlsOwnsSet and IlsUsesSet provide member functions to manipulate set-relations. Their use is described in the examples below. For more information, see also the Rogue Wave® Server Reference Manual.

To find out whether an object associated with a given key belongs to a set-relation, you must call the function IlsOwnsSet::isIn or IlsUsesSet::isIn:

_flights.isIn("FOO030")

To add an object to a set-relation, you can use the function put or the insertion operator << in the following manner:

_flight<<new Flight("FOO030");

_flights.put(new Flight("FOO030"));

Duplicates are not allowed. If you try to put in a set two objects associated with the same key, the exception IlsAlreadyInSet will be thrown.

To remove an object from a relation-set, you can use the extraction operator >> as follows:

_flights>>foo030;

foo030 is a variable of type CFlightPR.

You can also use the function IlsOwnsSet::suppress or IlsUsesSet::suppress:

_flights.suppress("FOO030");

If there is no match for the key passed to the function, the exception IlsNotFound is thrown.

The function clear empties a set-relation at once:

_flights.clear();

If the minimal cardinality specified for the set is different from zero, a call to the clear function will throw the exception IlsMinCardViolated.

The function get returns the object associated with the specified key:

_flights.get("FOO030")

To get the number of objects in a set, use the function IlsOwnsSet::getCount or IlsUsesSet::getCount:

_flights.getCount();

Version 6.3