Returning or outputting a @tableVariable in SQL

Question

Is it possible to return or output a @tableVariable in SQL Server?
For example for the following stored procedure, how do I return the @TSV table variable?

ALTER PROCEDURE MyStoredProdecure
    @Parameter1 INT,
    @Parameter2 INT
AS
   BEGIN

   DECLARE @TSV TABLE
   (
      Transition_Set_Variable_ID INT,
      Passed BIT
   )

   INSERT INTO @TSV
   { some data }

END

Answer 1

You cannot do it directly. Table variables are valid for READONLY input.

If you have no other data being returned from the stored procedure, you can select from the @TSV at the end and have the caller capture the output, e.g.

ALTER PROCEDURE MyStoredProdecure
    @Parameter1 INT,
    @Parameter2 INT
AS
   BEGIN

   DECLARE @TSV TABLE
   (
      Transition_Set_Variable_ID INT,
      Passed BIT
   )

   INSERT INTO @TSV
   { some data }

   SELECT * FROM @TSV
END

Caller

DECLARE @outerTSV TABLE
(
   Transition_Set_Variable_ID INT,
   Passed BIT
);
insert into @outerTSV
exec MyStoredProdecure 1, 2;

Alternatively, if the SP is really as simple as you showed, turn it into a table valued function instead.

Answer 2

No, but you can write a table valued function that returns a table.

create function MyTVF
    @Parameter1 INT,
    @Parameter2 INT
returns @tsv table
   (
      Transition_Set_Variable_ID INT,
      Passed BIT
   )

AS
   BEGIN
   INSERT INTO @TSV
   { some data }
   return 
END

Answer 3

Table Valued Parameters can only be used for input only, not output.

Depending on what your end goal is, here are some options:

1. change the sproc to a table-valued function to return a TABLE, that can then be used inline in another statement

2. simply SELECT the data from the @TSV table var at the end of your sproc

3. return an XML OUTPUT parameter (get a grubby feeling suggesting this, but just to highlight one way to return multiple rows actually using an OUTPUT parameter)

If you go for a Table Valued Function, ideally create an inline one if it is simple as it looks in your case:

e.g.

CREATE FUNCTION dbo.Func() 
RETURNS TABLE 
AS
RETURN
(
    SELECT Something
    FROM Somewhere
    WHERE x = 1
)