| Author: Swapnil 20 Jul 2006 | Member Level: Gold | Rating:  Points: 2 |
Hi,
For Composite key, it is combination of two or more columns and work as primary key means u can not enter null, empty values and values entered in that column must be unique.
For Unique Key, it is one or combination of more columns in which only unique values can be entered but it accepts null values.
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| Author: Abhishek Arya 20 Jul 2006 | Member Level: Diamond | Rating: Points: 2 |
composite Key:
primary key that consists of more than one column. Also known as a Concatenated Key or Aggregate Key. For example, the LINE_ITEMS table may have a composite key on {orderID, itemNumber}.
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