Convert time float to format HH:mm sql server

Question

I need to format a float decimal number into a time format hour:minute.

I wrote this Scalar-Value Functions with an input float and output varchar(6):

CREATE FUNCTIONE formatOre ( @input float )
returns varchar(6) 
as
begin
declare @n float;
declare @hour int = floor(@input);
declare @minutes int = (select (@input - floor(@input)) * 60);
declare @val varchar(6)

set @val = right('00' + convert(varchar(2), @hour), 2) + ':' + right('00' + convert(varchar(2), @minutes), 2);

return @val

end

It looks like great, but not for everything records. This is my output:

select formatOre (0)    ---> 00:00
select formatOre (0.17) ---> 00:10
select formatOre (0.25) ---> 00:15
select formatOre (0.33) ---> 00:19
select formatOre (0.42) ---> 00:25
select formatOre (0.5)  ---> 00:30
select formatOre (0.58) ---> 00:34
select formatOre (0.67) ---> 00:40
select formatOre (0.75) ---> 00:45
select formatOre (0.83) ---> 00:49
select formatOre (0.92) ---> 00:55

As you can see from the results, there are 3 wrongs conversion: 0.33 = 00:19 // 0.58 = 00:34 // 0.83 = 00:49.

How do I set the correct output?

Answer 1

Use function FORMAT SQL 2012+ https://docs.microsoft.com/en-us/sql/t-sql/functions/format-transact-sql

DECLARE  @input float = 4.92    
SELECT FORMAT(FLOOR(@input)*100 + (@input-FLOOR(@input))*60,'00:00')

Answer 2

Not a fix to the problem but perhaps something you can utilize. Scalar functions are horrible for performance. But inline table valued functions are not. The function you posted can be very easily converted to an inline table valued function. Keep in mind that these must be ONLY a single select statement. If you have variables and such it become a multi-statement table valued function and the performance would be even worse than a scalar function.

Here is how you could convert that scalar into an inline table valued function.

CREATE FUNCTION formatOre 
(
    @input float 
)
returns table as return

select right('00' + convert(varchar(2), floor(@input)), 2) + ':' + right('00' + convert(varchar(2), floor((@input - floor(@input)) * 60)), 2)

Answer 3

You can Try this

 SELECT FORMAT(FLOOR(ColumnNAme) + (ColumnNAme -FLOOR(ColumnNAme)),'00.00') from TableName