Question

I’m dealing with a legacy system where I need to identify some bad records based on a column with a data type of Float.

Good records have a value of…

1
2
1.01
2.01

Bad records are anything such as..

1.009999999999999
2.003423785643000
3.009999990463260

I’ve tried a number of select statements where I Convert to Decimal and cast to a varchar and use the LEN() function but this don’t seem to work as the good records that are 1.01 become 1.0100000000000000

–Edit
I’m a little closer now as I have discovered I can do (Weight * 100) and all of the good records become whole number values such as 101,201,265,301,500, etc…
and bad ones such as 2.00999999046326 become 200.999999046326

Answer 1

This works on my SQL Server 2005 DB:

select len(cast(cast(1.01 as float) as varchar))

Result:

4

In fact, it even lets me skip the explicit varchar cast if I want to:

select len(cast(1.011 as float))

Result:

5

---

Update: First of all, I still needed the cast to varchar. Thinking otherwise was wrong. That said, I had this all working using strings and was about to post how. Then you I your update on mulitpling by 100 and realized that was the way to go. So here’s my code for testing both ways:

declare @test table ( c float)
insert into @test 
    select * from 
        ( select 14.0100002288818 as c union
          select 1.01 union
          select 2.00999999046326 union
          select 14.01
         ) t

select c,
  case when c = cast(cast(c as varchar) as float) AND LEN(cast(c as varchar))<=5 then 1 else 0 end,
  case when c * 100 = floor(c * 100) then 1 else 0 end
from @test