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samar
primary key and unique key
1 Answer(s)      3 years and 9 months ago
Posted in : SQL


hello,

What's the difference between a primary key and a unique key?


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October 28, 2010 at 5:39 PM


hii,

Unique key: column restricts entry of duplicate values but entry of null values is allowed.

Primary key: columns entry of duplicate as well as null values are restricted.



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