NULL: A NULL value in a table is a value that appears blank in the field. The NULL value is one that has been left blank during the creation of table. Two reason for inserting null values in the database : When the actual value is not known or if it doesn't exist, nulls can be introduced in a database...

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Chapter 3, Problem 19E

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NULL:

A NULL value in a table is a value that appears blank in the field. The NULL value is one that has been left blank during the creation of table.

Two reason for inserting null values in the database:

When the actual value is not known or if it doesn't exist, nulls can be introduced in a database...

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