EXCEPTION HANDLERS

Translation reference to convert Teradata EXCEPTION HANDLERS clause to Snowflake Scripting

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

Description

Teradata's single and multiple Exception Handlers are replaced by its equivalent handlers in Snowflake Scripting.

For more information regarding Teradata EXCEPTION HANDLERS, check here.

DECLARE < handler_type > HANDLER
  FOR  < condition_value_list > < handler_action > ;

Sample Source Patterns

SQLEXCEPTION HANDLER

Teradata

Single handler

IN -> Teradata_01.sql

CREATE PROCEDURE handlerSample ()
BEGIN
    DECLARE EXIT HANDLER FOR SQLEXCEPTION
        INSERT INTO Proc_Error_Table ('procSample', 'Failed SqlException');
    SELECT * FROM Proc_Error_Table;
END;

Multiple handlers

IN -> Teradata_02.sql

CREATE PROCEDURE handlerSample ()
BEGIN
    DECLARE ConditionByUser1 CONDITION;
    DECLARE EXIT HANDLER FOR SQLEXCEPTION
        INSERT INTO Proc_Error_Table ('procSample', 'Failed SqlException');
    DECLARE EXIT HANDLER FOR ConditionByUser1
        INSERT INTO Proc_Error_Table ('procSample', 'Failed ConditionByUser1');
    SELECT * FROM Proc_Error_Table;
END;

Snowflake Scripting

Single handler

OUT -> Teradata_01.sql

CREATE OR REPLACE PROCEDURE handlerSample ()
RETURNS VARCHAR
LANGUAGE SQL
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},"attributes":{"component":"teradata"}}'
EXECUTE AS CALLER
AS
$$
    BEGIN
         
        SELECT
            * FROM
            Proc_Error_Table;
    EXCEPTION
            WHEN other THEN
            INSERT INTO Proc_Error_Table
            VALUES ('procSample', 'Failed SqlException');
    END;
$$;

Multiple handlers

OUT -> Teradata_02.sql

CREATE OR REPLACE PROCEDURE handlerSample ()
RETURNS VARCHAR
LANGUAGE SQL
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"teradata"}}'
EXECUTE AS CALLER
AS
$$
    DECLARE
        ConditionByUser1 EXCEPTION;
    BEGIN
         
         
        SELECT
            * FROM
            Proc_Error_Table;
    EXCEPTION
            WHEN ConditionByUser1 THEN
            INSERT INTO Proc_Error_Table
            VALUES ('procSample', 'Failed ConditionByUser1');
            WHEN other THEN
            INSERT INTO Proc_Error_Table
            VALUES ('procSample', 'Failed SqlException');
    END;
$$;

User-Defined Handlers

Teradata

Query

IN -> Teradata_03.sql

CREATE PROCEDURE handlerSample ()
BEGIN
    DECLARE EXIT HANDLER FOR Custom1, Custom2, Custom3
      BEGIN
        SET Message1 = 'custom1 and custom2 and custom3';
      END;
    SELECT * FROM Proc_Error_Table;
END;

Snowflake Scripting

Query

OUT -> Teradata_03.sql

CREATE OR REPLACE PROCEDURE handlerSample ()
RETURNS VARCHAR
LANGUAGE SQL
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},"attributes":{"component":"teradata"}}'
EXECUTE AS CALLER
AS
$$
    BEGIN
         
        SELECT
            * FROM
            Proc_Error_Table;
    EXCEPTION
            WHEN Custom1 OR Custom2 OR Custom3 THEN
            BEGIN
                    Message1 := 'custom1 and custom2 and custom3';
            END;
    END;
$$;

Known Issues

CONTINUE Handler

A 'CONTINUE' handler in Teradata allows the execution to be resumed after executing a statement with errors. This is not supported by the exception blocks in Snowflake Scripting. Condition Handler Teradata reference documentation.

Teradata

Query

IN -> Teradata_04.sql

CREATE PROCEDURE handlerSample ()
BEGIN
    DECLARE CONTINUE HANDLER FOR SQLEXCEPTION
        INSERT INTO Proc_Error_Table ('spSample4', 'Failed SqlException');
    SELECT * FROM Proc_Error_Table;
END;

Snowflake Scripting

Query

OUT -> Teradata_04.sql

CREATE OR REPLACE PROCEDURE handlerSample ()
RETURNS VARCHAR
LANGUAGE SQL
COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},"attributes":{"component":"teradata"}}'
EXECUTE AS CALLER
AS
$$
    BEGIN
        !!!RESOLVE EWI!!! /*** SSC-EWI-TD0004 - NOT SUPPORTED SQL EXCEPTION ON CONTINUE HANDLER ***/!!!
        DECLARE CONTINUE HANDLER FOR SQLEXCEPTION
        INSERT INTO Proc_Error_Table
        VALUES ('spSample4', 'Failed SqlException');
        SELECT
            * FROM
            Proc_Error_Table;
    END;
$$;

Other not supported handlers

Handlers for SQLSTATE, SQLWARNING, and NOT FOUND are not supported

Teradata

Query

IN -> Teradata_05.sql

CREATE PROCEDURE handlerSample ()
BEGIN
    DECLARE EXIT HANDLER FOR SQLSTATE '42002', SQLWARNING, NOT FOUND
        INSERT INTO Proc_Error_Table ('procSample', 'Failed SqlState or SqlWarning or Not Found');
    SELECT * FROM Proc_Error_Table;
END;

Snowflake Scripting

Query

OUT -> Teradata_05.sql

CREATE OR REPLACE PROCEDURE handlerSample ()
RETURNS VARCHAR
LANGUAGE SQL
COMMENT = '{ "origin": "sf_sc", "name": "snowconvert", "version": {  "major": 0,  "minor": 0,  "patch": "0" }, "attributes": {  "component": "teradata",  "convertedOn": "07/04/2024" }}'
EXECUTE AS CALLER
AS
$$
    BEGIN
--        !!!RESOLVE EWI!!! /*** SSC-EWI-0058 - FUNCTIONALITY FOR 'SQLSTATE, SQLWARNING, NOT-FOUND TYPES HANDLER' IS NOT CURRENTLY SUPPORTED BY SNOWFLAKE SCRIPTING ***/!!!
--        DECLARE EXIT HANDLER FOR SQLSTATE '42002', SQLWARNING, NOT FOUND
--            INSERT INTO Proc_Error_Table ('procSample', 'Failed SqlState or SqlWarning or Not Found');
        SELECT
            * FROM
            Proc_Error_Table;
    END;
$$;

Related EWIS

1. SSC-EWI-0058: Functionality is not currently supported by Snowflake Scripting.
2. SSC-EWI-TD0004: Not supported SQL Exception on continue handler.