Yesterday I found one more function of sql server. NULLIF which returns the first expression if the two expressions are not equal. If the expressions are equal, NULLIF returns a null value of the type of the first expression. NULLIF function is available from Sql Server 2005.
Syntax :
NULLIF ( expression , expression )
Example :
The following example creates a budgets table to show a department (dept) its current budget (current_year) and its previous budget (previous_year). For the current year, NULL is used for departments with budgets that have not changed from the previous year, and 0
is used for budgets that have not yet been determined. To find out the
average of only those departments that receive a budget and to include
the budget value from the previous year (use the previous_year value, where the current_year is NULL), combine the NULLIF and COALESCE functions.
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| ISNULLIF Example |
