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LOG ERROR

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
$$
    DECLARE
--        --** SSC-FDM-0024 - FUNCTIONALITY FOR 'PL COLLECTION TYPE DEFINITION' IS NOT CURRENTLY SUPPORTED BY SNOWFLAKE SCRIPTING **
--        TYPE employee_ids_t IS TABLE OF source_table%ROWTYPE
--        INDEX BY PLS_INTEGER;
        employee_list VARIANT !!!RESOLVE EWI!!! /*** SSC-EWI-0062 - CUSTOM TYPE 'employee_ids_t' USAGE CHANGED TO VARIANT ***/!!!;
        FORALL INTEGER;
    BEGIN
--        --** SSC-FDM-0024 - FUNCTIONALITY FOR 'RECORDS AND COLLECTIONS' IS NOT CURRENTLY SUPPORTED BY SNOWFLAKE SCRIPTING **
--        SELECT *
--            BULK COLLECT INTO employee_list
--            FROM source_table
--            WHERE DepartmentID = procedure_example.department_id_in
                                                                   ;
        FORALL := ARRAY_SIZE(:employee_list);
          MERGE INTO target_table
          USING (SELECT * FROM
                (
                    SELECT
                        seq4() AS indx
                    FROM
                        TABLE(GENERATOR(ROWCOUNT => :FORALL))
                )) src
          ON (id = : employee_list[indx]:id)
        WHEN MATCHED THEN
        UPDATE SET
          name = : employee_list[indx]:Name
        WHEN NOT MATCHED THEN
        INSERT (Id, Name, DepartmentID)
        VALUES (:employee_list[indx]:Id, : employee_list[indx]:Name, : employee_list[indx]:DepartmentID)
--        --** SSC-FDM-OR0031 - THE ERROR LOGGING CLAUSE IN DML STATEMENTS IS NOT SUPPORTED BY SNOWFLAKE **
--          LOG ERRORS INTO error_table('MERGE INTO ERROR')
--          REJECT LIMIT UNLIMITED
                                ;
    END;
$$;

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-0062: Custom type usage changed to variant.

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

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

  6. SSC-FDM-0024: Functionality is not currently supported by Snowflake Scripting.

  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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