Question : SQL query:  Calulate ave of 2 columns

Greetings Experts,
I need some help with a query that takes one column, divides it by another and multiplies the result by 100 (ie percentage).  I need to account for scenarios where there will be 0's.  Here is a sample of the data

Study   TotalPulled   TotalEntered
A               0                     5
B                5                    1
C                5                    0

The result set I need would look like this

Study   TotalPulled   TotalEntered     PercentEntered
A               0                     5                   0
B                5                    1                   20
C                5                    0                     0

The calulation would be (totalEntered/totalpullled) * 100.   The first row is dividing by 0 and gives me an error.   This is an unusual case because technically there should not be 0 totalpulled but it can happen so I need to account for it.  I suppose just making the PercentEntered = 0 in this case will suffice so at least it raise a flag that something is wrong.  

Every way I do it I get a result a 0, even for row B, where it should be 20.  Thanks

Answer : SQL query:  Calulate ave of 2 columns

Use the following Query, which assumes your table is called scoretable. Please note the case statement is absolutely necessary to ensure that you only divide by TotalPulled when it is greater than Zero. If you do not include this case statement, you will get a divide by Zero error whenever the value of TotalPulled is Zero.

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SELECT Study, TotalPulled, TotalEntered, CASE WHEN TotalPulled > 0 THEN (CAST(TotalEntered AS FLOAT) / CAST(TotalPulled AS FLOAT)) * 100 ELSE 0 END AS PERCENTAGE FROM scoretable

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