Here's another little script to demonstrate the effect of using float. Although the local variable looks pretty good out of a simple "print @i", converting the value to decimal bears out the internal inaccuracy.

declare @i float

set @i = .1

while @i <= 10.0

begin

print @i

print convert(decimal(38,36),@i)

set @i = @i + .1

End

The first few rows returned are here:

0.1

0.100000000000000000000000000000000000

0.2

0.200000000000000000000000000000000000

0.3

0.300000000000000060000000000000000000

0.4

0.400000000000000000000000000000000000

0.5

0.500000000000000000000000000000000000

0.6

0.600000000000000000000000000000000000

0.7

0.700000000000000000000000000000000000

0.8

0.799999999999999880000000000000000000

0.9

0.899999999999999880000000000000000000

1

0.999999999999999880000000000000000000

and the last few are here:

9.6

9.599999999999981900000000000000000000

9.7

9.699999999999981500000000000000000000

9.8

9.799999999999981200000000000000000000

9.9

9.899999999999980800000000000000000000

10

9.999999999999980400000000000000000000

It's now obvious that 9.9999999999999804 is not equal to 10.