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What is an association table in SQL?
Association tables are used for many-to-many relationships between two objects. They consist of at least two foreign keys, each of which references one of the two objects.
What is an associative table in relationships?
An associative (or junction) table maps two or more tables together by referencing the primary keys (PK) of each data table. In effect, it contains a number of foreign keys (FK), each in a many-to-one relationship from the junction table to the individual data tables.
How do I map an association to a table?
Saves an association as a table with foreign keys to the tables that are linked by the association. Objects can handle multivalued fields quite easily by using collections as field values. Relational databases don’t have this feature and are constrained to sin-gle- valued fields only.
What are association classes?
In UML diagrams, an association class is a class that is part of an association relationship between two other classes. An association class is identical to other classes and can contain operations, attributes, as well as other associations.
What is an association relationship?
An association relationship can be represented as one-to-one, one-to-many, or many-to-many (also known as cardinality). Essentially, an association relationship between two or more objects denotes a path of communication (also called a link) between them so that one object can send a message to another.
What is unidirectional mapping?
The unidirectional mapping defines the relationship only on 1 of the 2 associated entities, and you can only navigate it in that direction. The bidirectional mapping models the relationship for both entities so that you can navigate it in both directions.
Which association uses inverse attributes?
An Inverse attribute is used to maintain the relationship between the parent and child class object. The inverse attribute is used only with bi-directional mappings such as one-to-many and many-to-many Hibernate mapping.