Diff between Composite key, Alternate Key, Candidate Key,
Primary Key, Unique Key, Super Key, Foreign Key



Diff between Composite key, Alternate Key, Candidate Key, Primary Key, Unique Key, Super Key, Forei..

Answer / sapan saxena

Super Key: All possible keys which can identify entities in
the table uniquely.
Primary Key: uniquely identify each entity in the table and
does not contain null and duplicate vales.
Composite key: The combination of two or more than two keys
which identifies entities uniquely.
Candidate Key: Nominee for the primary key.
Alternate Key: Rest of the candidate keys which is not the
primary key.
Unique Key: Same as primary key but can accept one null key
only.
Foreign Key: A foreign key is one or more columns whose
value must exist in the primary key of another table.

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