Question

First I am converting the value from the table as integer like

cast(convert(int, isnull(b.temp,0)) as varchar(500))

and then I would like to output values as written below for example

1 as 001
12 as 012
123 as 123

-1 as -001 
-15 as -015
-234 as -234

and if length of the integer value is more than 3 then do not display any value or remove it.
If integer has Minus(-) sign then it is not part of the length
so -001 is consider as length 3

so 001 and -001 is acceptable as length 3

How can I do that?

Answer 1

There really is no efficient way to do this, but I understand there are situations where this needs to be done. I would probably go about it with something like this turned into a function.

DECLARE @myInt as INT
    SET @myInt = -9

DECLARE @padding AS VARCHAR(1)
    SET @padding = '0'
DECLARE @length AS INT
    SET @length = 3 - LEN(ABS(@myInt))

DECLARE @result AS VARCHAR(5)
    SET @result = REPLICATE(@padding, @length) + cast(ABS(@myInt) as VARCHAR(3))
IF @myInt < 0   
        SET @result = '-' + @result

SELECT @result

This really should be done in code and not sql.