| slovo | definícia |
entity-relationship model
(foldoc) | entity-relationship model
The most common kind of {data
modelling}, proposed by Peter P. Chen in 1976, in which a
database is divided into "entities" and "relations".
Part of capturing the requirements of an application is
defining the entities involved and their relationships.
Together, these form an entity-relationship model.
Entities are the kinds of things or concepts the application
deals with, e.g. products, customers, sales transactions. A
relationship connects two entities and says how many instances
of each participate in the relationship - one-to-one,
one-to-many or many-to-many.
Entities and some relationships correspond to database
tables. A table corresponding to a relationship is also
known as a "join table" after the join database operation.
A model is represented graphically as an {entity-relationship
diagram}.
["The entity-relationship model: toward a unified view of
data", P.P. Chen, ACM Transactions on Database Systems 1:1 pp
9-36, 1976].
(2019-11-03)
|
| | podobné slovo | definícia |
entity-relationship model
(foldoc) | entity-relationship model
The most common kind of {data
modelling}, proposed by Peter P. Chen in 1976, in which a
database is divided into "entities" and "relations".
Part of capturing the requirements of an application is
defining the entities involved and their relationships.
Together, these form an entity-relationship model.
Entities are the kinds of things or concepts the application
deals with, e.g. products, customers, sales transactions. A
relationship connects two entities and says how many instances
of each participate in the relationship - one-to-one,
one-to-many or many-to-many.
Entities and some relationships correspond to database
tables. A table corresponding to a relationship is also
known as a "join table" after the join database operation.
A model is represented graphically as an {entity-relationship
diagram}.
["The entity-relationship model: toward a unified view of
data", P.P. Chen, ACM Transactions on Database Systems 1:1 pp
9-36, 1976].
(2019-11-03)
|
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