To provide some background, I am currently working on a project of transitioning an Access database and its code to SQL.
In the process I changed Access data types of Double
to Float
in SQL Server; I did this because these data types are closely related and because my database performs a lot of division and multiplication (something I heard floats were best for).
Another issue of converting the database arose in the fact that Access uses bankers rounding whereas SQL does not; I went out and found two UD bankers rounding functions, both are not yielding consistent bankers rounding results as they should.
Is this inconsistency something I should expect when trying to run these bankers rounding functions (which include subtraction and addition) on float numbers?
The following are the two functions...
FUNCTION [dbo].[RB](@Val FLOAT, @Digits INT)
RETURNS FLOAT
AS
BEGIN
RETURN CASE WHEN ABS(@Val - ROUND(@Val, @Digits, 1)) * POWER(10, @Digits+1) = 5
THEN ROUND(@Val, @Digits, CASE WHEN CONVERT(INT, ROUND(ABS(@Val) *
POWER(10,@Digits), 0, 1)) % 2 = 1 THEN 0 ELSE 1 END)
ELSE ROUND(@Val, @Digits)
END
END
FUNCTION [dbo].[RoundBanker]
( @Amt NUMERIC(38,16)
, @RoundToDecimal TINYINT
)
RETURNS NUMERIC(38,16)
AS
BEGIN
DECLARE @RoundedAmt NUMERIC(38,16)
, @WholeAmt INT
, @Decimal TINYINT
, @Ten NUMERIC(38,16)
SET @Ten = 10.0
SET @WholeAmt = ROUND(@Amt,0, 1 )
SET @RoundedAmt = @Amt - @WholeAmt
SET @Decimal = 16
WHILE @Decimal > @RoundToDecimal
BEGIN
SET @Decimal = @Decimal - 1
IF 5 = ( ROUND(@RoundedAmt * POWER( @Ten, @Decimal + 1 ) ,0,1) -
(ROUND(@RoundedAmt * POWER( @Ten, @Decimal ) ,0,1) * 10) )
AND 0 = cast( ( ROUND(@RoundedAmt * POWER( @Ten, @Decimal ) ,0,1) -
(ROUND(@RoundedAmt * POWER( @Ten, @Decimal - 1 ) ,0,1) * 10) )
AS INTEGER ) % 2
SET @RoundedAmt = ROUND(@RoundedAmt,@Decimal, 1 )
ELSE
SET @RoundedAmt = ROUND(@RoundedAmt,@Decimal, 0 )
END
RETURN ( @RoundedAmt + @WholeAmt )
END