Given Letter, Get Next Letter in Alphabet

Question

I have letter \"a\", \"b\", \"c\". I would like my results to be \"b\", \"c\", \"d\" in TSQL respectively. Would what I use to achieve this?

Answer 1

3 letters alfabetic counter with two SQL procedures

(a, b...z, aa, ab...zy, zz, aaa...zzz):

SET QUOTED_IDENTIFIER OFF
GO
SET ANSI_NULLS ON
GO

alter procedure letraMas
@letraEntra as char( 1),
@letraSale as char( 1) OUTPUT,
@seLleva as bit  OUTPUT

as

--set @letraEntra = 'w'
--set @letraSale = 'm'
set @seLleva = 0

select
@letraSale = CASE
        WHEN @letraEntra = '' or (@letraEntra is null) or @letraEntra = 'z'
        THEN 'a'
    WHEN @letraEntra < 'z'
        THEN CHAR (ASCII( @letraEntra) + 1)
end

if @letraEntra = 'z' set @seLleva = 1

return

---

SET QUOTED_IDENTIFIER OFF
GO
SET ANSI_NULLS ON
GO

/* USO:
declare
@tareaEntra as char(3),
@tareaSale as char(3)
set @tareaEntra = 'xzz'
       EXEC tareaMas @tareaEntra, @tareaSale OUTPUT
*/
alter procedure tareaMas
@tareaEntra as char( 3),
@tareaSale as char( 3) OUTPUT

as
declare @charU as char(1 )     -- char de U_nidades albabéticas
declare @charD as char(1 )     -- char de D_ecenas albabéticas
declare @charC as char(1 )     -- char de C_entenas albabéticas
declare @letraSale as char(1 )        -- char de C_entenas albabéticas
declare @seLleva as bit

set @tareaEntra   = right('   ' + rtrim (@tareaEntra), 3)

set @charU = substring(@tareaEntra , 3, 1)
set @charD = substring(@tareaEntra , 2, 1)
set @charC = substring(@tareaEntra , 1, 1)

EXEC letraMas @charU, @letraSale OUTPUT, @seLleva OUTPUT
set @charU = @letraSale
if @seLleva = 1
BEGIN
        EXEC letraMas @charD, @letraSale OUTPUT, @seLleva OUTPUT
        set @charD = @letraSale
        if @seLleva = 1
        BEGIN
               EXEC letraMas @charC, @letraSale OUTPUT, @seLleva OUTPUT
               set @charC = @letraSale
        END
END

set @tareaSale = ltrim(@charC + @charD + @charU)
return