VARIABLES

Translation spec for Package Variables

Description

PACKAGE VARIABLES can be declared either in the package declaration or in the PACKAGE BODY. Due to its behavior, these variables are converted into Snowflake session variables so each usage or assignment is translated to its equivalent in Snowflake.

Oracle Variable declaration syntax

variable datatype [ [ NOT NULL] {:= | DEFAULT} expression ] ;

Sample Source Patterns

Sample auxiliary code

Oracle

create table table1(id number);

Snowflake

Variable declaration

Oracle

Query

CREATE OR REPLACE PACKAGE PKG1 AS
	package_variable NUMBER:= 100;
END PKG1;

Snowflake Scripting

Query

CREATE SCHEMA IF NOT EXISTS SCHEMA1_PKG1;

SET "SCHEMA1_PKG1.PACKAGE_VARIABLE" = '' || (100);

Variable Usage

Package variable usages are transformed into the Snowflake GETVARIABLE function which accesses the current value of a session variable. An explicit cast is added to the original variable data type in order to maintain the functional equivalence in the operations where these variables are used.

Oracle

Query

CREATE OR REPLACE PACKAGE PKG1 AS
	PROCEDURE procedure1;
	package_variable NUMBER:= 100;
END PKG1;

CREATE OR REPLACE PACKAGE BODY PKG1 AS
	PROCEDURE procedure1 AS
	BEGIN
		INSERT INTO TABLE1(ID) VALUES(package_variable);
	END;
END PKG1;

CALL SCHEMA1.PKG1.procedure1();

SELECT * FROM TABLE1;

Result

Snowflake

Query

CREATE SCHEMA IF NOT EXISTS SCHEMA1_PKG1;

/*** MSC-WARNING - MSCEWI3034 - PACKAGE PROCEDURE DECLARATION HEADING IS NOT NECESSARY IN SNOWFLAKE ***/
  /*	PROCEDURE procedure1;*/

SET "SCHEMA1_PKG1.PACKAGE_VARIABLE" = '' || (100);

CREATE OR REPLACE PROCEDURE SCHEMA1_PKG1.procedure1 ()
RETURNS VARCHAR
LANGUAGE SQL
EXECUTE AS CALLER
AS
$$
BEGIN
        INSERT INTO SCHEMA1.TABLE1(ID) VALUES(GETVARIABLE('SCHEMA1_PKG1.PACKAGE_VARIABLE') :: NUMBER);
END;
$$;

CALL SCHEMA1_PKG1.procedure1();

SELECT * FROM
PUBLIC.TABLE1;

Result

Variable regular assignment

When a package variable is assigned using the := operator, the assignation is replaced by a SnowConvert UDF called UPDATE_PACKAGE_VARIABLE_STATE which is an abstraction of the Snowflake SETVARIABLE function.

Oracle

Query

CREATE OR REPLACE PACKAGE PKG1 AS
	PROCEDURE procedure1;
	package_variable NUMBER:= 100;
END PKG1;

CREATE OR REPLACE PACKAGE BODY PKG1 AS
	PROCEDURE procedure1 AS
	BEGIN
		package_variable := package_variable + 100;
		INSERT INTO TABLE1(ID) VALUES(package_variable);
	END;
END PKG1;

CALL PKG1.procedure1();

SELECT * FROM TABLE1;

Result

Snowflake

Query

CREATE SCHEMA IF NOT EXISTS PKG1;

----** MSC-WARNING - MSCEWI3034 - PACKAGE PROCEDURE DECLARATION HEADING IS NOT NECESSARY IN SNOWFLAKE **
--PROCEDURE procedure1;

SET "PKG1.PACKAGE_VARIABLE" = '' || (100);

/*** MSC-INFORMATION - MSCINF0054 - PACKAGE BODY CONVERSION RATE IS AFFECTED BY ITS INNER ELEMENTS ***/
 

--** MSC-WARNING - MSCEWI1050 - MISSING DEPENDENT OBJECT "TABLE1" **
CREATE OR REPLACE PROCEDURE PKG1.procedure1 ()
RETURNS VARCHAR
LANGUAGE SQL
EXECUTE AS CALLER
AS
$$
	BEGIN
		--** MSC-WARNING - MSCEWI3122 - PACKAGE VARIABLE ASSIGNMENT WAS TRANSFORMED TO CUSTOM UDF **
		CALL UPDATE_PACKAGE_VARIABLE_STATE_UDF('PKG1.PACKAGE_VARIABLE', TO_VARCHAR(GETVARIABLE('PKG1.PACKAGE_VARIABLE') :: NUMBER + 100));
		INSERT INTO TABLE1(ID) VALUES(GETVARIABLE('PKG1.PACKAGE_VARIABLE') :: NUMBER);
	END;
$$;

CALL PKG1.procedure1();

--** MSC-WARNING - MSCEWI1050 - MISSING DEPENDENT OBJECT "TABLE1" **

SELECT * FROM
	TABLE1;

Result

Variable assignment as an output argument

When a package variable is used as an output argument a new variable is declared inside the procedure, this variable will catch the output argument value of the procedure, and then the variable will be used to update the session variable which refers to the package variable using the UPDATE_PACKAGE_VARIABLE_STATE mentioned above. For more information check de output parameters transformation.

Oracle

Query

CREATE OR REPLACE PACKAGE PKG1 AS
	PROCEDURE procedure1;
	PROCEDURE procedure2(out_param OUT NUMBER);
	package_variable NUMBER:= 100;
END PKG1;

CREATE OR REPLACE PACKAGE BODY PKG1 AS
	PROCEDURE procedure1 AS
	BEGIN
		procedure2(package_variable);
		INSERT INTO TABLE1(ID) VALUES(package_variable);
	END;
	PROCEDURE procedure2 (out_param OUT NUMBER) AS
	BEGIN
		out_param := 1000;
	END;
END PKG1;

CALL PKG1.procedure1();

Result

Snowflake

Query

CREATE SCHEMA IF NOT EXISTS PKG1;

----** MSC-WARNING - MSCEWI3034 - PACKAGE PROCEDURE DECLARATION HEADING IS NOT NECESSARY IN SNOWFLAKE **
--PROCEDURE procedure1;

----** MSC-WARNING - MSCEWI3034 - PACKAGE PROCEDURE DECLARATION HEADING IS NOT NECESSARY IN SNOWFLAKE **
--	PROCEDURE procedure2(out_param OUT NUMBER);

SET "PKG1.PACKAGE_VARIABLE" = '' || (100);

/*** MSC-INFORMATION - MSCINF0054 - PACKAGE BODY CONVERSION RATE IS AFFECTED BY ITS INNER ELEMENTS ***/
 

--** MSC-WARNING - MSCEWI1050 - MISSING DEPENDENT OBJECT "TABLE1" **
CREATE OR REPLACE PROCEDURE PKG1.procedure1 ()
RETURNS VARCHAR
LANGUAGE SQL
EXECUTE AS CALLER
AS
$$
	DECLARE
		PKG1_PACKAGE_VARIABLE VARIANT;
		call_results VARIANT;
	BEGIN
		call_results := (
			CALL PKG1.
			procedure2(:PKG1_PACKAGE_VARIABLE)
		);
		--** MSC-WARNING - MSCEWI1082 - AUTO-GENERATED CODE IN ORDER TO SUPPORT OUT PARAMETERS IN SNOWFLAKE SCRIPTING **
		PKG1_PACKAGE_VARIABLE := :call_results;
		--** MSC-WARNING - MSCEWI3122 - PACKAGE VARIABLE ASSIGNMENT WAS TRANSFORMED TO CUSTOM UDF **
		CALL UPDATE_PACKAGE_VARIABLE_STATE_UDF('PKG1.PACKAGE_VARIABLE', TO_VARCHAR(:PKG1_PACKAGE_VARIABLE));
		INSERT INTO TABLE1(ID) VALUES(GETVARIABLE('PKG1.PACKAGE_VARIABLE') :: NUMBER);
	END;
$$;

CREATE OR REPLACE PROCEDURE PKG1.procedure2 (out_param
--** MSC-WARNING - MSCEWI1083 - OUTPUT PARAMETERS ARE NOT SUPPORTED BUT FUNCTIONALITY IS BEING EMULATED **
NUMBER(38, 18))
RETURNS VARIANT
LANGUAGE SQL
EXECUTE AS CALLER
AS
$$
	BEGIN
		out_param := 1000;
		--** MSC-WARNING - MSCEWI1082 - AUTO-GENERATED CODE IN ORDER TO SUPPORT OUT PARAMETERS IN SNOWFLAKE SCRIPTING **
		RETURN null;
	END;
$$;

CALL PKG1.procedure1();

Result

Known Issues

No issues were found.

Related EWIs

1. MSCEWI1082: Auto-Generated code in order to support output parameters in Snowflake Scripting.

2. MSCEWI3122: Package Variable Assignment transformation.