Question

I have a table in SQL Server 2008 that looks kind of like this:

ID   I1  I2 ...  IN
-------------------------
1    2   3  ..... 2
2    0   0  ..... 0 
3    2   1  ..... 5

Where IN is about 9 columns. What I need to do is count the number of rows, but skipping rows where the values of I1..IN are 0’s. I’m new to SQL and I have basically something like this:

SELECT COUNT(ID) AS Expr1, 
       COUNT(I1) AS Expr2, 
       COUNT(I2) AS Expr3, 
       COUNT(IN) AS ExprN 
 FROM [mytable] 
WHERE (Expr2 !=0) 
  AND (Expr3 != 0) 
  AND (ExprN != 0)

I imagine there is an easier and more efficient way of doing this? I need to ensure that all of the column entries are 0 (other than the ID). I would prefer not to rely on a single column being 0 or not to make the determination. I working with a database somebody already created and these 0’s should have been NULLS.

Thanks!

Answer 1

SELECT COUNT(ID) AS Expr1, 
       COUNT(I1) AS Expr2, 
       COUNT(I2) AS Expr3, 
       COUNT(IN) AS ExprN 
 FROM [mytable] 
WHERE (I1 + I2 + I3 + I4 + [... +] IN) <> 0

… but I’m still not sure this meets the problem you’re trying to solve. COUNT(I1) will return the same as COUNT(I2) because they’ll be non-NULL in all the rows. Are you trying to find the number of rows with non-zero values?

SELECT COUNT(ID) AS Expr1,
       SUM(CASE WHEN I1 = 0 THEN 0 ELSE 1 END) as Expr2,
       SUM(CASE WHEN I2 = 0 THEN 0 ELSE 1 END) as Expr3,
       SUM(CASE WHEN IN = 0 THEN 0 ELSE 1 END) as ExprN,
 FROM [mytable] 
WHERE (I1 + I2 + I3 + I4 + [... +] IN) <> 0