This is a translation reference to convert Oracle functions to snowflake.
General Description
Most Oracle UDFs and UDFs inside packages, are being transformed to Snowflake Stored Procedures, to maintain functional equivalence, due to Snowflake UDFs having some limitations executing DML (Data Manipulation Language) statements.
Some parts in the output code are omitted for clarity reasons.
Create Function
Oracle
IN -> Oracle_01.sql
--Additional Params: -t JavaScript
CREATE OR REPLACE FUNCTION FUN1(PAR1 VARCHAR)
RETURN VARCHAR
IS
VAR1 VARCHAR(20);
VAR2 VARCHAR(20);
BEGIN
SELECT COL1 INTO VAR1 FROM TABLE1 where col1 = 1;
VAR2 := PAR1 || VAR1;
RETURN VAR2 ;
END;
Snowflake
OUT -> Oracle_01.sql
CREATE OR REPLACE FUNCTION FUN1 (PAR1 VARCHAR)
RETURNS VARCHAR
LANGUAGE SQL
COMMENT = '{ "origin": "sf_sc", "name": "snowconvert", "version": { "major": 0, "minor": 0, "patch": "0" }, "attributes": { "component": "oracle", "convertedOn": "11/13/2024", "domain": "test" }}'
AS
$$
WITH declaration_variables_cte1 AS
(
SELECT
(
SELECT COL1
FROM
TABLE1
where col1 = 1) AS VAR1,
NVL(PAR1 :: STRING, '') || NVL(VAR1 :: STRING, '') AS
VAR2
)
SELECT
VAR2
FROM
declaration_variables_cte1
$$;
Function inside Package
Oracle
IN -> Oracle_02.sql
--Additional Params: -t JavaScript
CREATE OR REPLACE PACKAGE BODY pkg1 AS
FUNCTION f1(PAR1 VARCHAR) RETURN VARCHAR IS
VAR1 VARCHAR(20);
VAR2 VARCHAR(20);
BEGIN
SELECT COL1 INTO VAR1 FROM TABLE1 where col1 = 1;
VAR2 := PAR1 || VAR1;
RETURN VAR2 ;
END f1;
END pkg1;
Snowflake
OUT -> Oracle_02.sql
CREATE OR REPLACE FUNCTION pkg1.f1(PAR1 VARCHAR)
RETURNS VARCHAR
LANGUAGE SQL
COMMENT = '{ "origin": "sf_sc", "name": "snowconvert", "version": { "major": 0, "minor": 0, "patch": "0" }, "attributes": { "component": "oracle", "convertedOn": "11/13/2024", "domain": "test" }}'
AS
$$
WITH declaration_variables_cte1 AS
(
SELECT
(
SELECT COL1
FROM
TABLE1
where col1 = 1) AS VAR1,
NVL(PAR1 :: STRING, '') || NVL(VAR1 :: STRING, '') AS
VAR2
)
SELECT
VAR2
FROM
declaration_variables_cte1
$$;
Return data type mapping
Oracle PL SQL type
Snowflake equivalent
NUMBER
FLOAT
LONG
VARCHAR
VARCHAR2
STRING
BLOB
BINARY
BFILE
BINARY
Call
Inside queries
Calls of functions that were transformed to procedures inside queries are converted into a an empty Snowflake JavaScript UDF. This Snowflake UDF is generated in the STUB_UDF.sql file inside the UDF Helpers directory.
Oracle
IN -> Oracle_03.sql
CREATE VIEW VIEW1 AS SELECT FUN1(COL2) FROM TABLE1;
CREATE VIEW VIEW2 AS SELECT PKG1.F1(COL1) FROM TABLE1;
Snowflake
OUT -> Oracle_03.sql
CREATE OR REPLACE VIEW VIEW1
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}'
AS
SELECT FUN1(COL2) !!!RESOLVE EWI!!! /*** SSC-EWI-0073 - PENDING FUNCTIONAL EQUIVALENCE REVIEW FOR 'FUN1' NODE ***/!!! FROM
TABLE1;
CREATE OR REPLACE VIEW VIEW2
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}'
AS
SELECT PKG1.F1(COL1) !!!RESOLVE EWI!!! /*** SSC-EWI-0073 - PENDING FUNCTIONAL EQUIVALENCE REVIEW FOR 'PKG1.F1' NODE ***/!!! FROM
TABLE1;
Inside other functions or stored procedures
Oracle
The functions that are converted to procedures are called using the EXEC Snowflake helper.
Oracle
IN -> Oracle_04.sql
--Additional Params: -t JavaScript
CREATE OR REPLACE FUNCTION FUN1(x NUMBER) RETURN NUMBER IS
VAR1 NUMBER;
BEGIN
-- FUN2 is another UDF
VAR1 := FUN2(pkg1.f1(X, FUN2(10)));
RETURN VAR1;
END f1;
Snowflake:
OUT -> Oracle_04.sql
CREATE OR REPLACE FUNCTION FUN1 (x 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": "11/13/2024", "domain": "test" }}'
AS
$$
WITH declaration_variables_cte1 AS
(
SELECT
FUN2(pkg1.f1(X, FUN2(10) !!!RESOLVE EWI!!! /*** SSC-EWI-0073 - PENDING FUNCTIONAL EQUIVALENCE REVIEW FOR 'FUN2' NODE ***/!!!) !!!RESOLVE EWI!!! /*** SSC-EWI-0073 - PENDING FUNCTIONAL EQUIVALENCE REVIEW FOR 'pkg1.f1' NODE ***/!!!) !!!RESOLVE EWI!!! /*** SSC-EWI-0073 - PENDING FUNCTIONAL EQUIVALENCE REVIEW FOR 'FUN2' NODE ***/!!! AS
-- FUN2 is another UDF
VAR1
)
SELECT
VAR1
FROM
declaration_variables_cte1
$$;
Oracle
IN -> Oracle_05.sql
--Additional Params: -t JavaScript
CREATE OR REPLACE FUNCTION FUN1(x NUMBER) RETURN NUMBER IS
VAR1 NUMBER;
BEGIN
-- FUN2 is another UDF
VAR1 := FUN2(X);
RETURN VAR1;
END f1;
Snowflake
OUT -> Oracle_05.sql
CREATE OR REPLACE FUNCTION FUN1 (x 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": "11/13/2024", "domain": "test" }}'
AS
$$
WITH declaration_variables_cte1 AS
(
SELECT
FUN2(X) !!!RESOLVE EWI!!! /*** SSC-EWI-0073 - PENDING FUNCTIONAL EQUIVALENCE REVIEW FOR 'FUN2' NODE ***/!!! AS
-- FUN2 is another UDF
VAR1
)
SELECT
VAR1
FROM
declaration_variables_cte1
$$;
Different cases and limitations
Functions with DMLs
These functions cannot be executed in queries in Oracle, so their usage wont be limited when transforming them to Snowflake Procedures.
Oracle
IN -> Oracle_06.sql
--Additional Params: -t JavaScript
CREATE OR REPLACE FUNCTION FUN1(x NUMBER)
RETURN NUMBER IS
VAR1 NUMBER;
BEGIN
VAR1 := VAR1 + 1;
INSERT INTO TABLE1(col1, col2) VALUES(X, VAR1);
UPDATE TABLE2 SET COL1 = VAR1 WHERE ID = X;
RETURN VAR1;
END FUN1;
Snowflake
OUT -> Oracle_06.sql
--** SSC-FDM-0029 - USER DEFINED FUNCTION WAS TRANSFORMED TO SNOWFLAKE PROCEDURE **
CREATE OR REPLACE PROCEDURE FUN1 (x FLOAT)
RETURNS FLOAT
LANGUAGE JAVASCRIPT
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},"attributes":{"component":"oracle"}}'
EXECUTE AS CALLER
AS
$$
// SnowConvert Helpers Code section is omitted.
let VAR1;
VAR1 = VAR1 + 1;
// ** SSC-EWI-0022 - ONE OR MORE IDENTIFIERS IN THIS STATEMENT WERE CONSIDERED PARAMETERS BY DEFAULT. REFERENCED TABLE NOT FOUND. **
EXEC(`INSERT INTO TABLE1(col1, col2) VALUES(?, ?)`,[X,VAR1]);
// ** SSC-EWI-0022 - ONE OR MORE IDENTIFIERS IN THIS STATEMENT WERE CONSIDERED PARAMETERS BY DEFAULT. REFERENCED TABLE NOT FOUND. **
EXEC(`UPDATE TABLE2
SET COL1 = ?
WHERE ID = ?`,[VAR1,X]);
return VAR1;
$$;
Functions with only one SELECT INTO
These functions are transformed to Snowflake SQL functions by removing the INTO part of the select.
Oracle
IN -> Oracle_07.sql
CREATE OR REPLACE FUNCTION FUN1(PAR1 VARCHAR)
RETURN VARCHAR
IS
VAR1 VARCHAR(20);
BEGIN
SELECT COL1 INTO VAR1 FROM TABLE1 where col1 = PAR1;
RETURN VAR1;
END;
Snowflake
OUT -> Oracle_07.sql
CREATE OR REPLACE FUNCTION FUN1 (PAR1 VARCHAR)
RETURNS VARCHAR
LANGUAGE SQL
COMMENT = '{ "origin": "sf_sc", "name": "snowconvert", "version": { "major": 0, "minor": 0, "patch": "0" }, "attributes": { "component": "oracle", "convertedOn": "11/13/2024", "domain": "test" }}'
AS
$$
WITH declaration_variables_cte1 AS
(
SELECT
(
SELECT COL1
FROM
TABLE1
where col1 = PAR1) AS VAR1
)
SELECT
VAR1
FROM
declaration_variables_cte1
$$;
Functions with only logic
UDFs that do not use any SQL statement are converted into Snowflake JavaScript UDFs.
When SQL built-in functions are included in the logic the user defined function is converted to a Snowflake procedure. Translation for built in functions to a JavaScript equivalent is planned to be delivered in the future.
Examples for built-in functions: UPPER(), TRIM(), ABS().
Oracle
IN -> Oracle_08.sql
--Additional Params: -t JavaScript
CREATE OR REPLACE FUNCTION FUN1(x NUMBER)
RETURN NUMBER IS
VAR1 NUMBER;
BEGIN
IF x < 5 THEN
VAR1 := 1;
ELSE
VAR1 := 0;
END IF;
RETURN VAR1;
END FUNC01;
Snowflake
OUT -> Oracle_08.sql
CREATE OR REPLACE FUNCTION FUN1 (x 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": "11/13/2024", "domain": "test" }}'
AS
$$
WITH declaration_variables_cte1 AS
(
SELECT
CASE
WHEN x < 5
THEN 1
ELSE 0
END AS VAR1
)
SELECT
VAR1
FROM
declaration_variables_cte1
$$;
Functions with more than one SQL statement
UDFs transformed into procedures cannot be called from a query.
Oracle
IN -> Oracle_09.sql
--Additional Params: -t JavaScript
CREATE OR REPLACE FUNCTION FUN1(x NUMBER)
RETURN NUMBER IS
VAR1 NUMBER;
BEGIN
SELECT COL1 INTO VAR1 FROM TABLE1 WHERE ID = X;
IF VAR1 < 5 THEN
VAR1 := 1;
ELSE
VAR1 := 0;
END IF;
UPDATE TABLE1 SET COL1 = VAR1 WHERE ID = X;
RETURN VAR1;
END FUN1;
Snowflake
OUT -> Oracle_09.sql
--** SSC-FDM-0029 - USER DEFINED FUNCTION WAS TRANSFORMED TO SNOWFLAKE PROCEDURE **
CREATE OR REPLACE PROCEDURE FUN1 (x FLOAT)
RETURNS FLOAT
LANGUAGE JAVASCRIPT
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},"attributes":{"component":"oracle"}}'
EXECUTE AS CALLER
AS
$$
// SnowConvert Helpers Code section is omitted.
let VAR1;
// ** SSC-EWI-0022 - ONE OR MORE IDENTIFIERS IN THIS STATEMENT WERE CONSIDERED PARAMETERS BY DEFAULT. REFERENCED TABLE NOT FOUND. **
[VAR1] = EXEC(`SELECT
COL1
FROM
TABLE1
WHERE ID = ?`,[X]);
if (VAR1 < 5) {
VAR1 = 1;
} else {
VAR1 = 0;
}
// ** SSC-EWI-0022 - ONE OR MORE IDENTIFIERS IN THIS STATEMENT WERE CONSIDERED PARAMETERS BY DEFAULT. REFERENCED TABLE NOT FOUND. **
EXEC(`UPDATE TABLE1
SET COL1 = ?
WHERE ID = ?`,[VAR1,X]);
return VAR1;
$$;
Functions with only logic and built-in SQL functions
This transformation is planned to be delivery in the future, currently all functions are being transformed to stored procedures.
Oracle
IN -> Oracle_10.sql
--Additional Params: -t JavaScript
CREATE OR REPLACE FUNCTION FUN1(x FLOAT)
RETURN NUMBER IS
VAR1 NUMBER;
BEGIN
IF TRUNC(X) < 5 THEN
VAR1 := 1;
ELSE
VAR1 := 0;
END IF;
RETURN VAR1;
END FUNC01;
Current transformation to Snowflake
OUT -> Oracle_10.sql
CREATE OR REPLACE FUNCTION FUN1 (x FLOAT)
RETURNS NUMBER(38, 18)
LANGUAGE SQL
COMMENT = '{ "origin": "sf_sc", "name": "snowconvert", "version": { "major": 0, "minor": 0, "patch": "0" }, "attributes": { "component": "oracle", "convertedOn": "11/13/2024", "domain": "test" }}'
AS
$$
WITH declaration_variables_cte1 AS
(
SELECT
CASE
WHEN TRUNC(X) < 5
THEN 1
ELSE 0
END AS VAR1
)
SELECT
VAR1
FROM
declaration_variables_cte1
$$;
RETURN CASE
The transformation is the same transformation when the CASE is use to assign a variable. You can check the transformation of CASE in the PL/SQL section.
Oracle
IN -> Oracle_11.sql
--Additional Params: -t JavaScript
CREATE OR REPLACE FUNCTION FUN1 (flag FLOAT)
RETURN NUMBER IS
BEGIN
return CASE flag
WHEN 1 THEN 'one'
WHEN 2 THEN 'two'
WHEN 3 THEN 'three'
WHEN 4 THEN 'four'
ELSE 'unknown' END;
END FUN1;
SnowFlake
OUT -> Oracle_11.sql
CREATE OR REPLACE FUNCTION FUN1 (flag FLOAT)
RETURNS NUMBER(38, 18)
LANGUAGE SQL
COMMENT = '{ "origin": "sf_sc", "name": "snowconvert", "version": { "major": 0, "minor": 0, "patch": "0" }, "attributes": { "component": "oracle", "convertedOn": "11/13/2024", "domain": "test" }}'
AS
$$
SELECT
CASE flag
WHEN 1 THEN 'one'
WHEN 2 THEN 'two'
WHEN 3 THEN 'three'
WHEN 4 THEN 'four'
ELSE 'unknown' END
$$;
Known Issues
No issues were found.
Related EWIs
SSC-EWI-0022: One or more identifiers in this statement were considered parameters by default.
