problem with multi statement table valued function, what am I doing wrong? - sql-server

Question

I having problems with this function, seems like #idUsuario and #passCorrecto aren't getting any value, so, when I use this variables in the where clause I'm not getting any result data.
ALTER FUNCTION [dbo].[login](#usuario varchar(20), #password varchar(20))
RETURNS #info TABLE (nombre varchar(70) not null, tipo varchar(30) not null)
AS
BEGIN
DECLARE #idUsuario int = dbo.usuarioExiste(#usuario)
DECLARE #passCorrecto bit = dbo.passwordCorrecto(#idUsuario, #password)
INSERT #info
SELECT
usuarios.nombreUsuario, tiposUsuarios.tipoUsuario
FROM
usuarios
LEFT JOIN
tiposUsuarios
ON
usuarios.idTipoUsuario = tiposUsuarios.idTipoUsuario
WHERE
usuarios.idUsuario = #idUsuario and
usuarios.estatus = 'ACTIVO' and
#passCorrecto = 1
RETURN
END
What am I doing wrong?
EDIT
Here are the function used above:
ALTER FUNCTION [dbo].[usuarioExiste]
(
#usuario varchar(20)
)
RETURNS integer
AS
BEGIN
DECLARE #idUsuario integer
SELECT
#idUsuario = idUsuario
FROM
usuarios
WHERE
usuario = #usuario
if #idUsuario is null begin
set #idUsuario = 0
end
RETURN #idUsuario
END
ALTER FUNCTION [dbo].[passwordCorrecto]
(
#usuario varchar(20),
#password varchar(20)
)
RETURNS bit
AS
BEGIN
DECLARE #esCorrecto bit
SELECT
#esCorrecto = case when password = #password then 1 else 0 end
FROM
usuarios
WHERE
usuario = #usuario
RETURN #esCorrecto
END
EDIT 2
As suggested by Beth, I created new functions that returns the values that I need like this:
CREATE FUNCTION [dbo].[usuarioExisteTest]
(
#usuario varchar(20)
)
RETURNS int
AS
BEGIN
declare #idUsuario int;
set #idUsuario = 1;
return (#idUsuario);
END;
By doing this I'm getting the data I need, am I setting the values to return the wrong way in the original functions?
DECLARE #idUsuario integer
SELECT
#idUsuario = idUsuario
FROM
usuarios
WHERE
usuario = #usuario

Answer 1

I know SQL Server 2008 supports the combined DECLARE/assign, but have you tried separating them?
DECLARE #idUsuario int
SET idUsuario = dbo.usuarioExiste(#usuario)
DECLARE #passCorrecto bit
SET passCorrecto = dbo.passwordCorrecto(#idUsuario, #password)
From BOL
Assigns a value to the variable
in-line. The value can be a constant
or an expression, but it must either
match the variable declaration type or
be implicitly convertible to that
type.
Of course, a udf is an expression, but is it possible there is some anomaly when used in DECLARE (like when you use a udf in CHECK constraint: it's not reliable). Or DECLARE ins a udf for some reason.
Please humour me. Try it.
Also, you have no "failsafe" inside dbo.passwordCorrecto which means it could return NULL which will always evaluate to false in the outer udf.

Answer 2

try printing the values of the variables after you declare them. If they aren't set correctly, try calling the functions in a new query window instead of within [dbo].[login]. That should help identify the problem.

Answer 3

I've found a solution, seem like using select #var = some_value doesn't work well. See this:
A SELECT statement that contains a variable assignment cannot be used to also perform typical result set retrieval operations.
These are the fixed functions:
usuarioExiste
CREATE FUNCTION [dbo].[usuarioExiste]
(
#usuario varchar(20)
)
RETURNS int
AS
BEGIN
declare #idUsuario int = 0;
set #idUsuario = (
select
idUsuario
from
usuarios
where
usuario = #usuario);
if #idUsuario is null begin
set #idUsuario = 0;
end;
return (#idUsuario);
END;
passwordCorrecto
CREATE FUNCTION [dbo].[passwordCorrecto]
(
#idUsuario int,
#password varchar(20)
)
RETURNS bit
AS
BEGIN
declare #esCorrecto bit = 'false';
set #esCorrecto = (
select
case when password = #password then 'true' else 'false' end
from
usuarios
where
usuarios.idUsuario = #idUsuario);
return (#esCorrecto);
END;
and login
CREATE FUNCTION [dbo].[login](#usuario varchar(20), #password varchar(20))
RETURNS #info TABLE (nombre varchar(70) not null, tipo varchar(30) not null)
AS
BEGIN
DECLARE #idUsuario int = dbo.usuarioExistetest(#usuario);
DECLARE #passCorrecto bit = dbo.passwordCorrectotest(#idUsuario, #password);
INSERT #info
SELECT
usuarios.nombreUsuario, tiposUsuarios.tipoUsuario
FROM
usuarios
LEFT JOIN
tiposUsuarios
ON
usuarios.idTipoUsuario = tiposUsuarios.idTipoUsuario
WHERE
usuarios.idUsuario = #idUsuario and
usuarios.estatus = 'ACTIVO' and
#passCorrecto = 'true';
RETURN
END;