Entities have attributes and have relationships with other entities. They have an entity name; usually names are required to be unique. Entities are often implemented as a record comprising a number of fields.
Attributes are usually represented in a data dictionary and describe the characteristic features of the entity. Each attribute is named; usually names of attributes are required to be unique. Attributes are often implemented as fields with values.
Each relationship has two names (a forward and a reverse name); usually relationship names are required to be unique. There can be more than one relationship between a pair of entities.
See also ERA diagram.
"ERA model." A Dictionary of Computing. . Encyclopedia.com. (August 19, 2018). http://www.encyclopedia.com/computing/dictionaries-thesauruses-pictures-and-press-releases/era-model
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