ALTER FUNCTION [dbo].[fChuyenCoDauThanhKhongDau](@inputVar NVARCHAR(MAX) )
RETURNS NVARCHAR(MAX)
AS
BEGIN    
    IF (@inputVar IS NULL OR @inputVar = '')  RETURN ''
   
    DECLARE @RT NVARCHAR(MAX)
    DECLARE @SIGN_CHARS NCHAR(256)
    DECLARE @UNSIGN_CHARS NCHAR (256)
 
    SET @SIGN_CHARS = N'ăâđêôơưàảãạáằẳẵặắầẩẫậấèẻẽẹéềểễệếìỉĩịíòỏõọóồổỗộốờởỡợớùủũụúừửữựứỳỷỹỵýĂÂĐÊÔƠƯÀẢÃẠÁẰẲẴẶẮẦẨẪẬẤÈẺẼẸÉỀỂỄỆẾÌỈĨỊÍÒỎÕỌÓỒỔỖỘỐỜỞỠỢỚÙỦŨỤÚỪỬỮỰỨỲỶỸỴÝ' + NCHAR(272) + NCHAR(208)
    SET @UNSIGN_CHARS = N'aadeoouaaaaaaaaaaaaaaaeeeeeeeeeeiiiiiooooooooooooooouuuuuuuuuuyyyyyAADEOOUAAAAAAAAAAAAAAAEEEEEEEEEEIIIIIOOOOOOOOOOOOOOOUUUUUUUUUUYYYYYDD'
 
    DECLARE @COUNTER int
    DECLARE @COUNTER1 int
   
    SET @COUNTER = 1
    WHILE (@COUNTER <= LEN(@inputVar))
    BEGIN  
        SET @COUNTER1 = 1
        WHILE (@COUNTER1 <= LEN(@SIGN_CHARS) + 1)
        BEGIN
            IF UNICODE(SUBSTRING(@SIGN_CHARS, @COUNTER1,1)) = UNICODE(SUBSTRING(@inputVar,@COUNTER ,1))
            BEGIN          
                IF @COUNTER = 1
                    SET @inputVar = SUBSTRING(@UNSIGN_CHARS, @COUNTER1,1) + SUBSTRING(@inputVar, @COUNTER+1,LEN(@inputVar)-1)      
                ELSE
                    SET @inputVar = SUBSTRING(@inputVar, 1, @COUNTER-1) +SUBSTRING(@UNSIGN_CHARS, @COUNTER1,1) + SUBSTRING(@inputVar, @COUNTER+1,LEN(@inputVar)- @COUNTER)
                BREAK
            END
            SET @COUNTER1 = @COUNTER1 +1
        END
        SET @COUNTER = @COUNTER +1
    END
    SET @inputVar = replace(@inputVar,'','')
    RETURN @inputVar
END