OBJECT RELATIONAL MAPPING FOR RELATIONAL DATABASES

摘要

Methods, systems, and apparatus, including computer programs encoded on computer storage media, for enforcing a mapping between entities in a database and aggregates in an application framework. One of the methods includes maintaining a mapping between entities represented in a relational database and respective corresponding objects in a program being executed by an application framework, wherein the relational database includes one or more relations defining an m-to-n mapping relationship between entities in a first relation of the relational database and respective entities in a second relation of the relational database. In response to receiving a request to populate a program object corresponding to an entity in the first relation of the relational database, the relational database is queried to obtain values for one or more attributes of the entity in the first relation and a plurality of identifiers that each identify a respective entity in the second relation of the relational database. The program object is populated with an aggregate having a complete collection of identifiers representing the m-to-n relationship in the database.