The data model in the ModelerNext to the Enterprise Structure Model, the Business Function Model, and the Business Process Model, the data model is the fourth type of diagram you can model in the Modeler. When you create or modify an entity relationship diagram, the following buttons are available in the Modeler. An entity type represents a cluster of associated data. There are two alternative entity types. To change the entity type, right-click an entity type, point to Type, and click one of these two options:
To link a LN table to an entity type, complete these steps:
To link an underlying entity relationship diagram to an entity type:
A relationship defines a relation between two entity types. The cardinality of a relationship defines the expected number of related occurrences for each of the two entity types. To change the cardinality of a relationship:
You can show that one way or both ways of the relationship are optional. To make a relationship optional:
The subtype relationship is a relationship between a subtype and a supertype; it is used to indicate that the attributes of the supertype also apply to the subtype. The diagram shows the relationships between versions, entity types, entity type categories, and database tables in the Modeler.  The relationship between tables, entity types and versions as
shown in the Process Modeler Workbench Sessions used in the Modeler The following sessions are only accessible from the Modeler:
To modify the fields and indices of the tables linked to an entity type, double-click the entity type icon, or right-click an entity type, point to Редактировать, and click Таблицы. To modify the field or index data, in the Window that appears, click Show Table Fields icon or Show Table Indices. The reverse-engineering procedure Instead of creating entity relationship diagrams from scratch, you can use reverse engineering when you create a data model consisting of LN tables. Reverse engineering lets you use information from an existing database. You can either select entity types that have not been used before in entity relationship diagrams, or generate a new set of entity types for which entity relationships or entity relationship diagrams already exist. Figure 14.8 shows the two sessions that make up the procedure for reverse engineering.  The reverse engineering procedure Создать типы сущностей и связей на базе словаря данных ERP (tgerm1210m000) To generate entity types and entity-type relationships by reverse engineering, use the Создать типы сущностей и связей на базе словаря данных ERP (tgerm1210m000) session. Only LN tables entity types can be created by means of reverse engineering. To start this session:
The newly generated entity types and entity relationships can be used in existing or new entity-relationship diagrams. To generate entity types and relationships from LN tables:
Создать диаграммы связи сущностей на основе типов (tgerm1220m000) To select a range of entity types for which you want to create entity-relationship, use the Создать диаграммы связи сущностей на основе типов (tgerm1220m000) session. To start this session:
To create entity relationship diagrams from entity types and entity type relationships, complete these steps:
Примечание If you select the Переписать check box, entity relationship diagrams that already exist in the selected version are overwritten by the newly created diagrams.
| |||