[SQL Server 2005] Mysterious problem with CASE statement

[Pradeep1210]

Hi,
When I perform some calcualtion in a case statement, it appends spaces randomly to the end of it. (From what I observed, it tries to make the length of the output equal to the longest possible value from all case conditions.)

declare @num int, @out varchar(10)
set @num = 2
set @out =  case @num
                when 1 then char(65) 
                when 2 then char(65) + char(65)
                when 3 then char(65) + char(65) + char(65)
                when 4 then char(65) + char(65) + char(65) + char(65)
                else char(65) + char(65) + char(65) + char(65) + char(65)
            end
print 'output = |' + @out + '|'
print 'length of output = ' + cast(len(@out) as varchar)

The output is:

output = |AA   |
length of output = 2

Notice that though the length of output is reported as 2, there are 3 spaces appended to it. So the actual length is 5.


If we repeat the same thing with constants we get the results what we expect:

declare @num int, @out varchar(10)
set @num = 2
set @out =  case @num
                when 1 then 'A' 
                when 2 then 'AA'
                when 3 then 'AAA'
                when 4 then 'AAAA'
                else 'AAAAA'
            end
print 'output = |' + @out + '|'
print 'length of output = ' + cast(len(@out) as varchar)

The output is:

output = |AA|
length of output = 2

Notice that there are no spaces appended now. The length reported is still 2 and this is correct.


Anyone knows the reason for this behaviour and how to get past this?