MS-SQL: Strip NON-Alphabetic Characters From String

Create Function [dbo].[RemoveNonAlphaCharacters](@Temp VarChar(1000))

Returns VarChar(1000)

AS

Begin

    Declare @KeepValues as varchar(50)

    Set @KeepValues = '%[^a-z]%'

    While PatIndex(@KeepValues, @Temp) > 0

        Set @Temp = Stuff(@Temp, PatIndex(@KeepValues, @Temp), 1, '')

    Return @Temp

End

TEST:

Select dbo.RemoveNonAlphaCharacters('abc1234def5678ghi90jkl')