问题
I have a number of type Decimal(8, 2) and have been using Substring to get fractional value.
E.g.)
declare @val decimal(8, 2), @strVal varchar(10)
set @val = 15.80
set @strVal = cast(@val as varchar)
select @val, substring(@strVal, charindex('.', @strVal), len(@strVal))
Is there a better way to simply get fractional value, .80 from @val without having to convert it to a character?
I am wondering if there is a built-in UDF (User-Defined Function) that would parse instead of having to rolling out my own version.
回答1:
Use the modulus (%) operator. You'll get 0.80.
Like this:
declare @val decimal(8, 2)
set @val = 15.80
select @val, @val % 1
回答2:
I think you mean the fractional value, not the decimal value. You already have teh decimal value. To get the fractional value, use Round, or Floor functions
Declare @Fraction Decimal(8,2)
Set @Fraction = @Val - Floor(@Val)
or
Set @Fraction = @Val - Round(@Val, 0)
回答3:
SET @val = (@val - ROUND(@val, 0, 1) * 100)
The ROUND(@val, 0, 1) should truncate the 15.80 into a 15.00. Then you subtract the 15 from the 15.80, and multiply the 0.80 by 100 to get 80 in numeric form.
The ROUND function requires the third parameter set to 1 to truncate the number. Otherwise, it would convert 15.80 into 16.00. See: http://msdn.microsoft.com/en-us/library/ms175003.aspx.
回答4:
For those that want to return the fractional value only... (i.e. without the decimal) SQLMenace posted a great way to do this using PARSENAME from this Article: How To Get Only Numbers After Decimal
An IMPORTANT NOTE before use: If their is no decimal SELECT PARSENAME((22),2) will return NULL... And SELECT PARSENAME((22 ),1) will return only the whole number... This can easily be handled by COALESCE or checking for a zero modulus... but it may not be practical in all uses
SELECT PARSENAME((22.777),1) -- Returns ONLY The number after decimal
SELECT PARSENAME((22.777),2) -- Returns ONLY The whole number
来源：https://stackoverflow.com/questions/1860542/what-would-be-a-reliable-way-to-get-fractional-value-from-a-number