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ERIL (Entity-Relationship and Inheritance Language) is a visual language for representing the data structure of a computer system. As its name suggests, ERIL is based on entity-relationship diagrams and class diagrams. ERIL combines the relational and object-oriented approaches to data modeling. == Overview == ERIL can be seen as a set of guidelines aimed at improving the readability of structure diagrams. These guidelines were borrowed from DRAKON, a variant of flowcharts created within the Russian space program. ERIL itself was developed by Stepan Mitkin. The ERIL guidelines for drawing diagrams: * Lines must be straight, either strictly vertical or horizontal. * Vertical lines mean ownership (composition). * Horizontal lines mean peer relationships (aggregation). * Line intersections are not allowed. * It is not recommended to fit the whole data model on a single diagram. Draw many simple diagrams instead. * The same class (table) can appear several times on the same diagram. * Use the following standard symbols to indicate the type of the relationship. * * One-to-one: a simple line. * * One-to-many, two-way: a line with a "paw". * * One-to-many, one-way: an arrow. * * Many-to-many: a line with two "paws". * Do not lump together inheritance and data relationships.〔(ERIL: a Visual Language for Data Modelling )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「ERIL」の詳細全文を読む スポンサード リンク
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