What is the difference between primary key & unique index ?
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Answer Posted / palash ghosh
1)Primary key creates an implicit culstered index on a
table, unique key does not create any implicit index.
2)Columns defined as primary key does not allow null values,
where as columns defined as unique can allow null values.
3)A table can have just one primary key (can be a composite
key) where as there can be multiple unique columns (keys).
4)Primary key is a unique key with the above mentioned
features.
| Is This Answer Correct ? | 9 Yes | 1 No |
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