I have a column X which is full of floats with decimals places ranging from 0 (no decimals) to 6 (maximum). I can count on the fact that there are no floats with greater than 6 decimal places. Given that, how do I make a new column such that it tells me how many digits come after the decimal?
I have seen some threads suggesting that I use CAST to convert the float to a string, then parse the string to count the length of the string that comes after the decimal. Is this the best way to go?
You can use something like this:
declare @v sql_variant set @v=0.1242311 select SQL_VARIANT_PROPERTY(@v, 'Scale') as Scale
This will return
I tried to make the above query work with a
float column but couldn't get it working as expected. It only works with a
sql_variant column as you can see here: http://sqlfiddle.com/#!6/5c62c/2
So, I proceeded to find another way and building upon this answer, I got this:
SELECT value, LEN( CAST( CAST( REVERSE( CONVERT(VARCHAR(50), value, 128) ) AS float ) AS bigint ) ) as Decimals FROM Numbers
Here's a SQL Fiddle to test this out: http://sqlfiddle.com/#!6/23d4f/29
To account for that little quirk, here's a modified version that will handle the case when the float value has no decimal part:
SELECT value, Decimals = CASE Charindex('.', value) WHEN 0 THEN 0 ELSE Len ( Cast( Cast( Reverse(CONVERT(VARCHAR(50), value, 128)) AS FLOAT ) AS BIGINT ) ) END FROM numbers
Here's the accompanying SQL Fiddle: http://sqlfiddle.com/#!6/10d54/11