Divide by zero error encountered

You may have a request to extract percentages and you encounter this dreaded error, when developing in SQL 2000, SQL 2005 or even SQL 2008.

The workaround for the Divide by zero error encountered. error is by using the NULLIF Function as the the example below demonstrates. The NULLIF function returns the first expression if the two expressions are not equivalent otherwise a NULL is returned.

Usage: SELECT NULLIF(col1, 0)

When col1 = 0 a NULL will be returned.

Example


CREATE TABLE #Products
(
Product VARCHAR(10),
Price DECIMAL(7, 2),
CostPrice DECIMAL(7, 2)
)


INSERT #Products SELECT 'A4 Books', 12.00, 6.00
INSERT #Products SELECT 'Pens', 0.10, 0.05
INSERT #Products SELECT 'Pencils', 0, 0.05


SELECT Product, (CostPrice / Price) * 100 AS PercentProfit FROM #Products


Will Produce the following Error:

(3 row(s) affected)

Server: Msg 8134, Level 16, State 1, Line 14
Divide by zero error encountered.

---------------------------------------------------------------------

SELECT Product, ((CostPrice/NULLIF(Price, 0))*100) AS PercentProfit
FROM #Products

Returns:

Product PercentProfit
---------- -----------------------
A4 Books 50.0000000000
Pens 50.0000000000
Pencils NULL


(3 row(s) affected)