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Difference between primary key and unique key ?
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Answer Posted / mohammad ali
-The column holding the primary key constraint cannot accept
null values.whereas colum holding the unique constraint can
accept null values.
-We can declare only one primary key in a table
but a table can have multiple unique key
-Clustered index is created on Primary key constraint and
non clustered unique indexes is created on Unique key constraint.
-Primary key columns automatically become NOT NULL (unique
keys can contain nulls).
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