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Difference between primary key and unique key ?
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Answer Posted / austin johnson
we can't insert a NULL value into to coloumn holding
primary key constrain.
where as we can insert a NULL value to a unique key feild.
Remember, both keys are used to identify the
rows/tuple/entry of the table uniquely.
so, only once u can enter a NULL value into the unique key
feild.
| Is This Answer Correct ? | 146 Yes | 57 No |
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