OUTPUT PARAMETERS
This article is about the current transformation of the output parameters and how their functionality is being emulated.
Description
An output parameter is a parameter whose value is passed out of the stored procedure, back to the calling SQL block. Since the output parameters are not supported by Snowflake Scripting, a solution has been implemented in order to emulate their functionality.
Sample Source Patterns
Single OUT parameter
The most basic scenario for OUT parameters is when the procedure only has one. In this case, we simply return the OUT parameter at the end of the procedure body.
The EXEC procedure has to be translated as well, for this a CALL is created, the parameters are passed without any modifier ("OUT" is removed), and subsequently, an assignment is done so the parameter is associated with it's respective resulting value.
Transact-SQL
-- Procedure with output parameter
CREATE PROCEDURE dbo.outmain
@name VARCHAR (255) OUTPUT
AS
SET @name = 'Jane';
GO
-- Auxiliary procedure that calls the main procedure
CREATE PROCEDURE dbo.outaux
AS
DECLARE @name VARCHAR (255);
EXEC dbo.outmain
@name = @name OUTPUT;Snowflake Scripting
-- Procedure with output parameter
CREATE OR REPLACE PROCEDURE dbo.outmain (NAME OUT STRING)
RETURNS VARCHAR
LANGUAGE SQL
COMMENT = '{ "origin": "sf_sc", "name": "snowconvert", "version": { "major": 0, "minor": 0, "patch": "0" }, "attributes": { "component": "transact", "convertedOn": "07/10/2025", "domain": "no-domain-provided" }}'
EXECUTE AS CALLER
AS
$$
BEGIN
NAME := 'Jane';
END;
$$;
-- Auxiliary procedure that calls the main procedure
CREATE OR REPLACE PROCEDURE dbo.outaux ()
RETURNS VARCHAR
LANGUAGE SQL
COMMENT = '{ "origin": "sf_sc", "name": "snowconvert", "version": { "major": 0, "minor": 0, "patch": "0" }, "attributes": { "component": "transact", "convertedOn": "07/10/2025", "domain": "no-domain-provided" }}'
EXECUTE AS CALLER
AS
$$
DECLARE
NAME VARCHAR(255);
BEGIN
CALL dbo.outmain(:NAME);
END;
$$;Multiple OUT parameters
When more than one OUT parameters are found, the RETURNS clause of the procedure changes to VARIANT. This is to accommodate the OBJECT_CONSTRUCT that is going to be used to store the values of the OUT parameters.
On top of that, a RETURN statement is added to the end of the procedure's body. This is where the OBJECT_COSNTRUCT is created and all the OUT parameter values are stored within it. This object will then be used by the caller to assign the parameters value to the corresponding result.
Transact-SQL
CREATE OR ALTER PROCEDURE basicProc (
@col1 INT OUT,
@col2 VARCHAR(10) OUT
) AS
BEGIN
SET @col1 = 4;
SET @col2 = 'test';
END;
CREATE OR ALTER PROCEDURE basicProcCall AS
BEGIN
DECLARE @var1 INT = 0;
DECLARE @var2 VARCHAR(10) = 'EMPTY';
EXEC basicProc @var1 OUT, @var2 OUT;
INSERT INTO TABLE1(col1, col2) VALUES (@var1, @var2);
END;
EXEC basicProcCall;Snowflake Scripting
CREATE OR REPLACE PROCEDURE basicProc (COL1 OUT INT, COL2 OUT STRING)
RETURNS VARCHAR
LANGUAGE SQL
COMMENT = '{ "origin": "sf_sc", "name": "snowconvert", "version": { "major": 0, "minor": 0, "patch": "0" }, "attributes": { "component": "transact", "convertedOn": "07/10/2025", "domain": "no-domain-provided" }}'
EXECUTE AS CALLER
AS
$$
BEGIN
COL1 := 4;
COL2 := 'test';
END;
$$;
CREATE OR REPLACE PROCEDURE basicProcCall ()
RETURNS VARCHAR
LANGUAGE SQL
COMMENT = '{ "origin": "sf_sc", "name": "snowconvert", "version": { "major": 0, "minor": 0, "patch": "0" }, "attributes": { "component": "transact", "convertedOn": "07/10/2025", "domain": "no-domain-provided" }}'
EXECUTE AS CALLER
AS
$$
DECLARE
VAR1 INT := 0;
VAR2 VARCHAR(10) := 'EMPTY';
BEGIN
CALL basicProc(:VAR1, :VAR2);
INSERT INTO TABLE1 (col1, col2) VALUES (:VAR1, :VAR2);
END;
$$;
CALL basicProcCall();OUT parameters and return values
Transact-SQL allows procedures to have return values. When a procedure has both a return value and OUT parameter(s), a similar approach to the Multiple OUT parameters scenario is followed. The original return value is treated as an OUT parameter would be treated, so it's stored within the OBJECT_CONSTRUCT and extracted inside the caller procedure.
Transact-SQL
-- Procedure with multiple output parameters
CREATE PROCEDURE dbo.outmain
@name VARCHAR (255) OUTPUT
AS
SET @name = 'Jane';
RETURN 0;
-- Auxiliary procedure that calls the main procedure
CREATE PROCEDURE dbo.outaux
AS
DECLARE @name VARCHAR (255);
DECLARE @returnValue INT;
EXEC @returnValue = dbo.outmain
@name = @name OUTPUT;Snowflake Scripting
-- Procedure with multiple output parameters
CREATE OR REPLACE PROCEDURE dbo.outmain (NAME OUT STRING)
RETURNS VARCHAR
LANGUAGE SQL
COMMENT = '{ "origin": "sf_sc", "name": "snowconvert", "version": { "major": 0, "minor": 0, "patch": "0" }, "attributes": { "component": "transact", "convertedOn": "07/10/2025", "domain": "no-domain-provided" }}'
EXECUTE AS CALLER
AS
$$
BEGIN
NAME := 'Jane';
RETURN 0;
END;
$$;
-- Auxiliary procedure that calls the main procedure
CREATE OR REPLACE PROCEDURE dbo.outaux ()
RETURNS VARCHAR
LANGUAGE SQL
COMMENT = '{ "origin": "sf_sc", "name": "snowconvert", "version": { "major": 0, "minor": 0, "patch": "0" }, "attributes": { "component": "transact", "convertedOn": "07/10/2025", "domain": "no-domain-provided" }}'
EXECUTE AS CALLER
AS
$$
DECLARE
NAME VARCHAR(255);
RETURNVALUE INT;
BEGIN
CALL dbo.outmain(:NAME);
END;
$$;Customer data type OUT parameters
when the output parameter is a customer type, the process is similar to a regular data type.
Transact-SQL
CREATE PROCEDURE procedure_udtype_out_params(
@p_employee_id INT,
@p_phone [dbo].[PhoneNumber] OUTPUT
) AS
BEGIN
SELECT @p_phone = phone
FROM employees
WHERE employee_id = @p_employee_id;
END;Snowflake Scripting
--** SSC-FDM-0007 - MISSING DEPENDENT OBJECTS "[dbo].[PhoneNumber]", "employees" **
CREATE OR REPLACE PROCEDURE procedure_udtype_out_params (P_EMPLOYEE_ID INT, P_PHONE OUT VARIANT /*** SSC-FDM-TS0015 - DATA TYPE DBO.PHONENUMBER IS NOT SUPPORTED IN SNOWFLAKE ***/)
RETURNS VARCHAR
LANGUAGE SQL
COMMENT = '{ "origin": "sf_sc", "name": "snowconvert", "version": { "major": 0, "minor": 0, "patch": "0" }, "attributes": { "component": "transact", "convertedOn": "07/10/2025", "domain": "no-domain-provided" }}'
EXECUTE AS CALLER
AS
$$
BEGIN
SELECT
phone
INTO
:P_PHONE
FROM
employees
WHERE
employee_id = :P_EMPLOYEE_ID;
END;
$$;Known Issues
No issues were found.
Related EWIs
SSC-EWI-0073: Pending Functional Equivalence Review.
SSC-FDM-TS0015: Data type is not supported in Snowflake.
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