pshvets (4/14/2009)

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Hello all.

I am trying to write a function which reverses passed string WITHOUT using any built-in functions

So if 'abc' is passed, it returns 'cba'

I want to use recursion. Here is what I got:

create function StringReverse

(

@InString varchar(20)

)

returns varchar(20)

AS

begin

declare @RevString varchar(20)

IF len(@InString) in (0,1)

set @RevString = @InString

ELSE

set @RevString =

(

dbo.StringReverse(substring(@InString, len(@InString)/2+1, len(@InString))

+

dbo.StringReverse(substring(@InString, 1, len(@InString)/2)))

)

return @RevString

end

It compiles fine, but when I call it, it throws an exception:

select dbo.StringReverse('abc')

Msg 217, Level 16, State 1, Line 1

Maximum stored procedure, function, trigger, or view nesting level exceeded (limit 32).

Why? Function calls itself at most 5 times:

Pass1 - RevString('c') + RevString('ab')

Pass2 - 'c' + (RevString(RevString('b') + RevString('a'))

Pass3 - 'cba'

Should I use a loop?

Thanks in advance for your help!

Pit