If we declare constraints Unique and Not null on a single
column then it will act as a Primary key, so what is the use
of primary key??
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Answer Posted / neha sinha
1) Primary key creates clustered index and unique key
creates non-clustered index. Performance wise clustered
index is fast so we need Primary key.
2)if we need more then one primary key in table than we can
use unique key+NOT NULL becous it behave as Primary key but
we cant define more than one column as primary key. :)
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