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Modeling: User's Guide |  |
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Primary keys are attributes/columns that an RDBMS uses to uniquely identify every row of a table. It is required that a non-abstract Entity2.2 defines one of its attributes to be a primary key. Within an entity you define attributes, relationships, and primary keys as well as the attributes that are ''used for locking'' (this we will not explained for now, as it it addresses a feature, optimistic locking, that is not yet supported). However, for primary keys, you should remember that we only support simple primary keys, i.e. primary keys with only one attribute; hence, please make sure that you have one, and only one, primary-key per entity.
Entities know their primary keys. Their are defined differently in PyModels
and in xml-model, see the respective sections
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Modeling: User's Guide | |
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