SSC-FDM-0029

User defined function was transformed to a Snowflake procedure.

This EWI is deprecated, please refer to SSC-EWI-0068 documentation

Severity

Low

Description

Snowflake user defined functions do not support the same features as Oracle or SQL Server. To maintain the functional equivalence the function is transformed to a Snowflake stored procedure. This will affect their usage in queries.

Example Code

SQL Server:

Input Code

IN -> SqlServer_01.sql

CREATE OR ALTER FUNCTION PURCHASING.FOO()
RETURNS INT
AS
BEGIN
    DECLARE @i int = 0, @p int;
    Select @p = COUNT(*) FROM PURCHASING.VENDOR
    
    WHILE (@p < 1000)
    BEGIN
        SET @i = @i + 1
        SET @p = @p + @i
    END
        
    IF (@i = 6)
        RETURN 1
    
    RETURN @p
END;

Output Code

OUT -> SqlServer_01.sql

--** SSC-FDM-0029 - USER DEFINED FUNCTION WAS TRANSFORMED TO SNOWFLAKE PROCEDURE **
CREATE OR REPLACE PROCEDURE PURCHASING.FOO ()
RETURNS VARCHAR
LANGUAGE SQL
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"transact"}}'
EXECUTE AS CALLER
AS
$$
    DECLARE
        I INT := 0;
        P INT;
    BEGIN
         
        Select
            COUNT(*)
        INTO
            :P
 FROM
            PURCHASING.VENDOR;
        WHILE (:P < 1000) LOOP
            I := :I + 1;
            P := :P + :I;
        END LOOP;
        IF ((:I = 6)) THEN
            RETURN 1;
        END IF;
        RETURN :P;
    END;
$$;

Oracle:

Input Code

IN -> Oracle_01.sql

CREATE FUNCTION employee_function (param1 in NUMBER) RETURN NUMBER is
  var1    employees.employee_ID%TYPE;
  var2    employees.manager_ID%TYPE;
  var3    employees.title%TYPE;
BEGIN
  SELECT employee_ID, manager_ID, title
  INTO var1, var2, var3
  FROM employees
    START WITH manager_ID = param1
    CONNECT BY manager_ID = PRIOR employee_id;
  RETURN var1;
EXCEPTION
   WHEN no_data_found THEN RETURN param1;
END employee_function;

Output Code

OUT -> Oracle_01.sql

--** SSC-FDM-0029 - USER DEFINED FUNCTION WAS TRANSFORMED TO SNOWFLAKE PROCEDURE **
CREATE OR REPLACE PROCEDURE employee_function (param1 NUMBER(38, 18))
RETURNS NUMBER(38, 18)
LANGUAGE SQL
COMMENT = '{ "origin": "sf_sc", "name": "snowconvert", "version": {  "major": 0,  "minor": 0,  "patch": "0" }, "attributes": {  "component": "oracle",  "convertedOn": "11/14/2024",  "domain": "test" }}'
EXECUTE AS CALLER
AS
$$
  DECLARE
    var1    employees.employee_ID%TYPE;
    var2    employees.manager_ID%TYPE;
    var3    employees.title%TYPE;
  BEGIN
    SELECT employee_ID, manager_ID, title
    INTO
      :var1,
      :var2,
      :var3
    FROM
      employees
      START WITH manager_ID = :param1
    CONNECT BY
      manager_ID = PRIOR employee_id;
    RETURN :var1;
  EXCEPTION
     WHEN no_data_found THEN
      RETURN :param1;
  END;
$$;

Recommendations

• Separate the inside queries to maintain the same logic.

• The source code may need to be restructured to fit with the Snowflake user-defined functions approach.

• If you need more support, you can email us at [email protected]