问题描述:

I have this table structure on a SQL Server 2008 R2 database:

`CREATE TABLE FormTest`

(

clientid char(10),

DateSelected date,

A int,

B int,

C int

)

I filled the table FormTest with the following information

`clientid DateSelected A B C`

x1 2006-06-09 65150 4921 1

x2 2006-05-05 155926 69092 1

x3 2006-01-20 95603 156892 1

x4 2006-01-20 30704 164741 1

x4 2006-02-03 65150 174834 1

x5 2006-04-28 59629 4921 1

x6 2006-01-27 30704 162356 1

x7 2006-06-30 65150 4921 1

x8 2006-07-10 65150 4921 1

And finally, I run this sql query:

`SELECT clientid, (((a+ b + c) / 3) / 216647 * 10) AS Formula1`

From FormTest

But then I got these results:

`clientid Formula1`

x1 0

x2 0

x3 0

x4 0

x4 0

x5 0

x6 0

x7 0

x8 0

Can anybody tell me what am I doing wrong?

It's because you are doing integer division. You should convert one of the operands to float, or decimal (depending on the precision and purpose of the calculation you are doing), using something like:

```
((CAST((a+ b + c) AS FLOAT) / 3) / 216647 * 10)
```

or possibly:

```
(((a+ b + c) / 3.0) / 216647.0 * 10)
```

You're performing integer arithmetic, so your results will always be rounded down to the nearest whole number. Since you're dividing by 3, then by 216647, based on the numeric inputs your result is getting rounded down to 0 every time. You'll need to use either a decimal (exact) or floating point (approximate) data type and/or casting if you want to get non-integer results.

```
declare @a int
declare @b int
declare @c int
set @a=65150
set @b=4921
set @c=1
select convert(float,((@[email protected][email protected])/ 216647.0 * 10) )
```