What are the different types of keys used in relational DBMS? What is the purpose of primary key? What is the difference between a primary key and unique key
Different types of keys in DBMS and their features
Hi
The different types of keys used in DBMS are: –
• Super Key
• Candidate Key
• Primary Key
• Foreign Key
• Alternate Key
• Unique Key
A primary key is a modification of a candidate key that neither allows NULL values nor allows repetitive values. A unique key however, allows NULL values but doesn’t allow repeated values.
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