An aggregation relationship (aggregation)
Aggregation relationship by a straight line with an arrow indicates the open diamonds, below A represents polymerized onto B, A or B of the composition;
Aggregation relationship is used to represent relationships between entities objects, represented by the whole configuration of the semantic part; for example, a staff of the plurality of sectors;
And a combination of different relationships are, and some are not strongly dependent on the whole, even if the whole does not exist, and some still exist; for example, the department revoked, people will not go away, they still exist;
Two combination relationship (composition)
With a combining relationship with filled diamonds represents straight arrows, as showing FIG composition A B, A or B of the composition;
And Paradigmatic as composition represented by semantic relationships may likewise constituted by a part of the whole; such as the company consisting of a plurality of sectors;
However, a combination of a special relationship is a strongly dependent aggregation relationship, if a whole does not exist, the part not exist; for example, the company does not exist, the sector will not exist;
