Composite primary key is a primary key, which consists of more than one column. The column combination guarantees the uniqueness of the PK.
A Composite Primary Key is a Composite Key, which is assigned as Primary.
Primary key is a single field or the least combination of fields that uniquely identifies each record in table. When the primary key consists of more than one field, when we are talking about composite primary key. Composite or not, is the most appropriate key to be main key of reference for the table.
The primary key must not be null and must contain only unique values.
Primary keys are mandatory for every table. When choosing a primary key from the pool of candidate keys, always choose a single simple key over a composite key.
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