Types of Keys
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Super Key - a group of single or multiple keys which identifies rows in a table
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Primary Key - a column or group of columns in a table that uniquely identify every row in that table
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Candidate Key - a set of attributes that uniquely identify tuples in a table. Candidate Key is a super key with no repeated attributes
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Alternate Key- a column or group of columns in a table that uniquely identify every row in that table
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Foreign Key - a column that creates a relationship between two tables. The purpose of Foreign keys is to maintain data integrity and allow navigation between two different instances of an entity
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Compound Key- has two or more attributes that allow you to uniquely recognize a specific record. It is possible that each column may not be unique by itself within the database
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Composite Key - an artificial key which aims to uniquely identify each record is called a surrogate key. These kind of key are unique because they are created when you don't have any natural primary key
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Surrogate Key - an artificial key which aims to uniquely identify each record is called a surrogate key. These kind ofkey are unique because they are created when you don't have any natural primary key
