Defining and transforming entity relationship-XML hybrid data models

摘要

An entity-relationship (ER)-eXtensible Markup Language (XML) hybrid data model includes an unmarked entity and an entity marked to be transformed as an XML column. In transforming the ER-XML hybrid data model to a physical data model, the unmarked entity is transformed to a table in the physical data model. It is determined whether the marked entity has an unmarked parent entity. If so, the marked entity, and the transitive closure of the marked entity, is transformed to an XML column in a table representing the unmarked parent entity in the physical data model, an XML schema document (XSD) for the XML column is generated, and the XSD is associated with the XML column. A relational-XML hybrid data model includes one or more XML columns marked to transform to a set of entities in the ER model by expanding the contents of the XSD associated with the XML column.

主权项

1. A method comprising:
providing an entity-relationship (ER)-extensible markup language (XML) hybrid data model of a relational database comprising XML data; receiving a user setting of a first annotation of a first entity in the ER-XML hybrid data model marking the first entity as not to be transformed as XML data; receiving a user setting of a second annotation of a second entity in the ER-XML hybrid data model marking the second entity as to be transformed as XML data; and transforming, by a computing processor, the ER-XML hybrid data model to a physical data model of the relational database, comprising:
based on the first annotation of the first entity marking the first entity as not to be transformed as XML data, transforming the first entity in the ER-XML hybrid data model to a first table in the physical data model;based on the second annotation of the second entity marking the second entity as to be transformed as XML data, determining whether the second entity has a parent entity in the ER-ML hybrid data model with a third annotation marking the parent entity as not to be transformed as XML data; andin response to determining that the second entity has the parent entity with the third annotation marking the parent entity as not to be transformed as XML data:
transforming the second entity and a transitive closure of the second entity to an XML column in a second table in the physical data model, the second table representing the parent entity in the ER-XML hybrid data model marked as not to be transformed as XML data;generating an XML schema document (XSD) for the XML column; andassociating the XSD with the XML column in the physical data model.