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Some parts in the output code are omitted for clarity reasons.

Description

The FORALL statement runs one DML statement multiple times, with different values in the VALUES and WHERE clauses. (Oracle PL/SQL Language Reference FORALL Statement).

FORALL index IN bounds_clause [ SAVE ] [ EXCEPTIONS ] dml_statement ;

Snowflake Scripting has no direct equivalence with the FORALL statement, however can be emulated with different workarounds to get functional equivalence.

Sample Source Patterns

Setup Data

Oracle

IN -> Oracle_01.sql
CREATE TABLE error_table (
    ORA_ERR_NUMBER$ NUMBER,
    ORA_ERR_MESG$ VARCHAR2(2000),
    ORA_ERR_ROWID$ ROWID,
    ORA_ERR_OPTYP$ VARCHAR2(2),
    ORA_ERR_TAG$ VARCHAR2(2000)
);

--departments
CREATE TABLE parent_table(
    Id INT PRIMARY KEY,
    Name VARCHAR2(10)
);

INSERT INTO parent_table VALUES (10, 'IT');
INSERT INTO parent_table VALUES (20, 'HR');
INSERT INTO parent_table VALUES (30, 'INFRA');

--employees
CREATE TABLE source_table(
    Id INT PRIMARY KEY,
    Name VARCHAR2(20) NOT NULL,
    DepartmentID INT REFERENCES parent_table(Id)
);

INSERT INTO source_table VALUES (101, 'Anurag111111111', 10); 
INSERT INTO source_table VALUES (102, 'Pranaya11111111', 20); 
INSERT INTO source_table VALUES (103, 'Hina11111111111', 30);

--a copy of source
CREATE TABLE target_table(
    Id INT PRIMARY KEY,
    Name VARCHAR2(10) NOT NULL,
    DepartmentID INT REFERENCES parent_table(Id)
);

INSERT INTO target_table VALUES (101, 'Anurag', 10);

Snowflake

OUT -> Oracle_01.sql
CREATE OR REPLACE TABLE error_table (
    "ORA_ERR_NUMBER$" NUMBER(38, 18) /*** SSC-FDM-0006 - NUMBER TYPE COLUMN MAY NOT BEHAVE SIMILARLY IN SNOWFLAKE. ***/,
    "ORA_ERR_MESG$" VARCHAR(2000),
    "ORA_ERR_ROWID$" VARCHAR(18) !!!RESOLVE EWI!!! /*** SSC-EWI-0036 - ROWID DATA TYPE CONVERTED TO VARCHAR ***/!!!,
    "ORA_ERR_OPTYP$" VARCHAR(2),
    "ORA_ERR_TAG$" VARCHAR(2000)
)
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}'
;

--departments
CREATE OR REPLACE TABLE parent_table (
        Id INT PRIMARY KEY,
        Name VARCHAR(10)
    )
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}'
;

INSERT INTO parent_table
VALUES (10, 'IT');

INSERT INTO parent_table
VALUES (20, 'HR');

INSERT INTO parent_table
VALUES (30, 'INFRA');

--employees
CREATE OR REPLACE TABLE source_table (
    Id INT PRIMARY KEY,
    Name VARCHAR(20) NOT NULL,
    DepartmentID INT REFERENCES parent_table (Id)
)
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}'
;

INSERT INTO source_table
VALUES (101, 'Anurag111111111', 10);

INSERT INTO source_table
VALUES (102, 'Pranaya11111111', 20);

INSERT INTO source_table
VALUES (103, 'Hina11111111111', 30);

--a copy of source
CREATE OR REPLACE TABLE target_table (
    Id INT PRIMARY KEY,
    Name VARCHAR(10) NOT NULL,
    DepartmentID INT REFERENCES parent_table (Id)
)
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}'
;

INSERT INTO target_table
VALUES (101, 'Anurag', 10);

1. MERGE INTO Inside a FORALL

Oracle

The three cases below have the same transformation to Snowflake Scripting and are functionally equivalent.

IN -> Oracle_02.sql
CREATE OR REPLACE PROCEDURE procedure_example (
    department_id_in   IN source_table.DepartmentID%TYPE)
IS
    TYPE employee_ids_t IS TABLE OF source_table%ROWTYPE
    INDEX BY PLS_INTEGER; 
    employee_list   employee_ids_t;
BEGIN
    SELECT *
        BULK COLLECT INTO employee_list
        FROM source_table
        WHERE DepartmentID = procedure_example.department_id_in;
    
    FORALL indx IN 1 .. employee_list.COUNT
      MERGE INTO target_table 
      USING (SELECT * FROM DUAL) src
      ON (id = employee_list(indx).id)
      WHEN MATCHED THEN
        UPDATE SET
          name = employee_list(indx).Name
      WHEN NOT MATCHED THEN
        INSERT (Id, Name, DepartmentID)
        VALUES (employee_list(indx).Id, employee_list(indx).Name, employee_list(indx).DepartmentID)
      LOG ERRORS INTO error_table('MERGE INTO ERROR') 
      REJECT LIMIT UNLIMITED;
        
END;

CALL procedure_example(10);

select * from target_table;
select * from error_table;

Snowflake

OUT -> Oracle_02.sql
CREATE OR REPLACE PROCEDURE procedure_example (department_id_in VARIANT !!!RESOLVE EWI!!! /*** SSC-EWI-OR0129 - TYPE ATTRIBUTE 'source_table.DepartmentID%TYPE' COULD NOT BE RESOLVED, SO IT WAS TRANSFORMED TO VARIANT ***/!!!)
RETURNS VARCHAR
LANGUAGE SQL
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},"attributes":{"component":"oracle"}}'
EXECUTE AS CALLER
AS
$$
    DECLARE
--        !!!RESOLVE EWI!!! /*** SSC-EWI-0058 - FUNCTIONALITY FOR 'PL COLLECTION TYPE DEFINITION' IS NOT CURRENTLY SUPPORTED BY SNOWFLAKE SCRIPTING ***/!!!
--        TYPE employee_ids_t IS TABLE OF source_table%ROWTYPE
--        INDEX BY PLS_INTEGER;
        employee_list VARIANT !!!RESOLVE EWI!!! /*** SSC-EWI-0062 - CUSTOM TYPE 'employee_ids_t' USAGE CHANGED TO VARIANT ***/!!!;
        FORALL INTEGER;
    BEGIN
        !!!RESOLVE EWI!!! /*** SSC-EWI-0058 - FUNCTIONALITY FOR 'RECORDS AND COLLECTIONS' IS NOT CURRENTLY SUPPORTED BY SNOWFLAKE SCRIPTING ***/!!!
        SELECT *
            BULK COLLECT INTO employee_list
            FROM source_table
            WHERE DepartmentID = procedure_example.department_id_in;
        FORALL := ARRAY_SIZE(:employee_list);
          MERGE INTO target_table
          USING (SELECT * FROM
                (
                    SELECT
                        seq4() AS indx
                    FROM
                        TABLE(GENERATOR(ROWCOUNT => :FORALL))
                )) src
          ON (id = : employee_list[indx]:id)
        WHEN MATCHED THEN
        UPDATE SET
          name = : employee_list[indx]:Name
        WHEN NOT MATCHED THEN
        INSERT (Id, Name, DepartmentID)
        VALUES (:employee_list[indx]:Id, : employee_list[indx]:Name, : employee_list[indx]:DepartmentID)
--        --** SSC-FDM-OR0031 - THE ERROR LOGGING CLAUSE IN DML STATEMENTS IS NOT SUPPORTED BY SNOWFLAKE **
--          LOG ERRORS INTO error_table('MERGE INTO ERROR')
--          REJECT LIMIT UNLIMITED
                                ;
    END;
$$;


CALL procedure_example(10);


select * from
    target_table;

select * from
    error_table;

The EWIs MSCCP0005 and SSC-PRF-0003 are added in every FETCH BULK COLLECT occurrence into FORALL statement.

2. FORALL With INSERT INTO

Oracle

IN -> Oracle_03.sql
CREATE OR REPLACE PROCEDURE myProcedure IS
    CURSOR cursorVariable IS
        SELECT * FROM table1;
    TYPE collectionTypeDefinition IS TABLE OF table1%ROWTYPE;
    collectionVariable collectionTypeDefinition;
BEGIN
    OPEN cursorVariable;
    LOOP
        FETCH cursorVariable BULK COLLECT INTO collectionVariable limit 2;
        EXIT WHEN collectionVariable.COUNT = 0;
        FORALL forIndex IN collectionVariable.FIRST..collectionVariable.LAST
            INSERT INTO table2 VALUES collectionVariable(forIndex);
        collectionVariable.DELETE;
    END LOOP;
    CLOSE cursorVariable;
END;

Snowflake

OUT -> Oracle_03.sql
CREATE OR REPLACE PROCEDURE myProcedure ()
RETURNS VARCHAR
LANGUAGE SQL
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}'
EXECUTE AS CALLER
AS
$$

    BEGIN
        --** SSC-PRF-0001 - THIS STATEMENT HAS USAGES OF CURSOR FETCH BULK OPERATIONS **
        --** SSC-PRF-0003 - FETCH INSIDE A LOOP IS CONSIDERED A COMPLEX PATTERN, THIS COULD DEGRADE SNOWFLAKE PERFORMANCE. **
        INSERT INTO table2
        (
            SELECT
                * FROM
                table1
        );
    END;
$$;

3. FORALL With Multiple Fetched Collections

Oracle

IN -> Oracle_04.sql
CREATE OR REPLACE PROCEDURE myProcedure IS
    CURSOR cursorVariable IS
        SELECT * FROM table1;
    column1Collection dbms_sql.NUMBER_table;
    column2Collection dbms_sql.NUMBER_table;
BEGIN
    OPEN cursorVariable;
    LOOP
        FETCH cursorVariable BULK COLLECT INTO column1Collection, column2Collection limit 20;
        EXIT WHEN column1Collection.COUNT = 0;
        FORALL forIndex IN 1..column1Collection.COUNT
            INSERT INTO table2 VALUES (
                column1Collection(forIndex),
                column2Collection(forIndex)
            );
    END LOOP;
    CLOSE cursorVariable;
END;

Snowflake

OUT -> Oracle_04.sql
CREATE OR REPLACE PROCEDURE myProcedure ()
RETURNS VARCHAR
LANGUAGE SQL
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}'
EXECUTE AS CALLER
AS
$$

    BEGIN
        --** SSC-PRF-0001 - THIS STATEMENT HAS USAGES OF CURSOR FETCH BULK OPERATIONS **
        --** SSC-PRF-0003 - FETCH INSIDE A LOOP IS CONSIDERED A COMPLEX PATTERN, THIS COULD DEGRADE SNOWFLAKE PERFORMANCE. **
        INSERT INTO table2
        (
            SELECT
                $1,
                $2
            FROM
                table1
        );
    END;
$$;

4. FORALL With Record of Collections

Oracle

IN -> Oracle_06.sql
CREATE OR REPLACE PROCEDURE myProcedure IS
    CURSOR cursorVariable IS
        SELECT * FROM table1;
    TYPE recordType IS RECORD(
        column1Collection dbms_sql.NUMBER_table,
        column2Collection dbms_sql.NUMBER_table
    );
    columnRecord recordType;
BEGIN
    OPEN cursorVariable;
    LOOP
        FETCH cursorVariable BULK COLLECT INTO columnRecord.column1Collection, columnRecord.column2Collection limit 20;
        FORALL forIndex IN 1..columnRecord.column1Collection.COUNT
            INSERT INTO table2 VALUES (
                columnRecord.column1Collection(forIndex),
                columnRecord.column2Collection(forIndex)
            );
        EXIT WHEN cursorVariable%NOTFOUND;
    END LOOP;
    CLOSE cursorVariable;
END;

Snowflake

OUT -> Oracle_06.sql
CREATE OR REPLACE PROCEDURE myProcedure ()
RETURNS VARCHAR
LANGUAGE SQL
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}'
EXECUTE AS CALLER
AS
$$

    BEGIN
        --** SSC-PRF-0001 - THIS STATEMENT HAS USAGES OF CURSOR FETCH BULK OPERATIONS **
        --** SSC-PRF-0003 - FETCH INSIDE A LOOP IS CONSIDERED A COMPLEX PATTERN, THIS COULD DEGRADE SNOWFLAKE PERFORMANCE. **
        INSERT INTO table2
        (
            SELECT
                $1,
                $2
            FROM
                table1
        );
    END;
$$;

5. FORALL With Dynamic SQL

Oracle

IN -> Oracle_07.sql
CREATE OR REPLACE PROCEDURE myProcedure IS
    cursorVariable SYS_REFCURSOR;
    TYPE collectionTypeDefinition IS
        TABLE OF table1%ROWTYPE;
    collectionVariable collectionTypeDefinition;
    query VARCHAR(200) := 'SELECT * FROM table1';
BEGIN
    OPEN cursorVariable FOR query;
    LOOP
        FETCH cursorVariable BULK COLLECT INTO collectionVariable;
        EXIT WHEN collectionVariable.COUNT = 0;
        FORALL forIndex IN collectionVariable.FIRST..collectionVariable.LAST
            INSERT INTO table2 VALUES collectionVariable(forIndex);
        collectionVariable.DELETE;
    END LOOP;
    CLOSE cursorVariable;
END;

Snowflake

OUT -> Oracle_07.sql
CREATE OR REPLACE PROCEDURE myProcedure ()
RETURNS VARCHAR
LANGUAGE SQL
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}'
EXECUTE AS CALLER
AS
$$
    DECLARE
        query VARCHAR(200) := 'SELECT * FROM
   table1';
    BEGIN
        --** SSC-PRF-0001 - THIS STATEMENT HAS USAGES OF CURSOR FETCH BULK OPERATIONS **
        --** SSC-PRF-0003 - FETCH INSIDE A LOOP IS CONSIDERED A COMPLEX PATTERN, THIS COULD DEGRADE SNOWFLAKE PERFORMANCE. **
        !!!RESOLVE EWI!!! /*** SSC-EWI-0030 - THE STATEMENT BELOW HAS USAGES OF DYNAMIC SQL. ***/!!!
        EXECUTE IMMEDIATE 'CREATE OR REPLACE TEMPORARY TABLE query AS ' || :query;
        INSERT INTO table2
        (
            SELECT
                *
            FROM
                query
        );
    END;
$$;

6. FORALL Without LOOPS

Oracle

IN -> Oracle_08.sql
CREATE OR REPLACE PROCEDURE  myProcedure IS
    TYPE collectionTypeDefinition IS TABLE OF table1%ROWTYPE;
    collectionVariable collectionTypeDefinition;
BEGIN
    SELECT * BULK COLLECT INTO collectionVariable FROM table1;
        FORALL forIndex IN 1..collectionVariable.COUNT
            INSERT INTO table2 VALUES (
                collectionVariable (forIndex).column1,
                collectionVariable (forIndex).column2
            );
        collectionVariable.DELETE;
END;

Snowflake

OUT -> Oracle_08.sql
CREATE OR REPLACE PROCEDURE myProcedure ()
RETURNS VARCHAR
LANGUAGE SQL
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}'
EXECUTE AS CALLER
AS
$$

    BEGIN
        --** SSC-PRF-0003 - FETCH INSIDE A LOOP IS CONSIDERED A COMPLEX PATTERN, THIS COULD DEGRADE SNOWFLAKE PERFORMANCE. **
        INSERT INTO table2
        (
            SELECT
                column1,
                column2
            FROM
                table1
        );
    END;
$$;

7. FORALL With UPDATE Statements

Oracle

IN -> Oracle_09.sql
CREATE OR REPLACE PROCEDURE myProcedure IS
    CURSOR cursorVariable IS
        SELECT * FROM table1;
    TYPE collectionTypeDefinition IS TABLE OF table1%ROWTYPE;
    collectionVariable collectionTypeDefinition;
BEGIN
    OPEN cursorVariable;
    LOOP
        FETCH cursorVariable BULK COLLECT INTO collectionVariable limit 2;
        EXIT WHEN collectionVariable.COUNT = 0;
        FORALL forIndex IN collectionVariable.FIRST..collectionVariable.LAST
            UPDATE table2 SET column1 = '54321' WHERE column2 = collectionVariable(forIndex).column2;
        collectionVariable.DELETE;
    END LOOP;
    CLOSE cursorVariable;
END;

Snowflake

OUT -> Oracle_09.sql
CREATE OR REPLACE PROCEDURE myProcedure ()
RETURNS VARCHAR
LANGUAGE SQL
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}'
EXECUTE AS CALLER
AS
$$

    BEGIN
        --** SSC-PRF-0001 - THIS STATEMENT HAS USAGES OF CURSOR FETCH BULK OPERATIONS **
        --** SSC-PRF-0003 - FETCH INSIDE A LOOP IS CONSIDERED A COMPLEX PATTERN, THIS COULD DEGRADE SNOWFLAKE PERFORMANCE. **
        UPDATE table2
            SET column1 = '54321'
            FROM
                (
                    SELECT
                        * FROM
                        table1) AS collectionVariable
            WHERE
                column2 = collectionVariable.column2;
    END;
$$;

8. FORALL With DELETE Statements

Oracle

IN -> Oracle_10.sql
CREATE OR REPLACE PROCEDURE myProcedure IS
    CURSOR cursorVariable IS
        SELECT * FROM table1;
    TYPE collectionTypeDefinition IS TABLE OF table1%ROWTYPE;
    collectionVariable collectionTypeDefinition;
BEGIN
    OPEN cursorVariable;
    LOOP
        FETCH cursorVariable BULK COLLECT INTO collectionVariable limit 2;
        EXIT WHEN collectionVariable.COUNT = 0;
        FORALL forIndex IN collectionVariable.FIRST..collectionVariable.LAST
            DELETE FROM table2 WHERE column2 = collectionVariable(forIndex).column2;
        collectionVariable.DELETE;
    END LOOP;
    CLOSE cursorVariable;
END;

Snowflake

OUT -> Oracle_10.sql
CREATE OR REPLACE PROCEDURE myProcedure ()
RETURNS VARCHAR
LANGUAGE SQL
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}'
EXECUTE AS CALLER
AS
$$

    BEGIN
        --** SSC-PRF-0001 - THIS STATEMENT HAS USAGES OF CURSOR FETCH BULK OPERATIONS **
        --** SSC-PRF-0003 - FETCH INSIDE A LOOP IS CONSIDERED A COMPLEX PATTERN, THIS COULD DEGRADE SNOWFLAKE PERFORMANCE. **
        DELETE FROM
            table2
        USING (
            SELECT
                * FROM
                table1) collectionVariable
                WHERE
            table2.column2 = collectionVariable.column2;
    END;
$$;

Known Issues

No issues were found.

Related EWIs

  1. SSC-EWI-0030: The statement below has usages of dynamic SQL.

  2. SSC-EWI-0036: Data type converted to another data type.

  3. SSC-EWI-0058: Functionality is not currently supported by Snowflake Scripting.

  4. SSC-EWI-0062: Custom type usage changed to variant.

  5. SSC-EWI-OR0129: TYPE attribute could not be resolved.

  6. SSC-FDM-0006: Number type column may not behave similarly in Snowflake.

  7. SSC-FDM-OR0031: The error logging clause in DML statements is not supported by Snowflake.

  8. SSC-PRF-0001: This statement has usages of cursor fetch bulk operations.

  9. SSC-PRF-0003: Fetch inside a loop is considered a complex pattern, this could degrade Snowflake performance.

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