DB2 FUNCTION EXCEPTION - sql

Question

I'm converting Oracle plsql function into DB2 plsql function.Below I mentioned the structure of Oracle and DB2 query.
CREATE FUNCTION FUNCTION_NAME (IN PARAMETER1 DATATYPE)
Return varchar(4000) IS
N_COLUMN1 varchar(1);
N_COLUMN2 INT;
N_COLUMN3 VARCHAR(2000);
BEGIN
SELECT A.COLUMN1,A.COLUMN2 INTO N_COLUMN1,N_COLUMN2 FROM TABLE A WHERE A.COLUMN1=PARAMETER1;
IF N_COLUMN1 = 'A' then N_COLUMN3:= 'NEW_A';
ELSEIF N_COLUMN1 = 'B' then N_COLUMN3:= 'NEW_B';
END IF;
exception when others then N_COLUMN3:= 'OTHERS'
RETURN N_COLUMN3;
END;
/
DB2 query:
CREATE FUNCTION FUNCTION_NAME (IN PARAMETER1 DATATYPE)
Returns varchar(4000)
BEGIN
declare N_COLUMN1 varchar(1);
declare N_COLUMN2 INT;
declare N_COLUMN3 VARCHAR(2000);
SELECT A.COLUMN1,A.COLUMN2 INTO N_COLUMN1,N_COLUMN2 FROM TABLE A WHERE A.COLUMN1=PARAMETER1;
IF N_COLUMN1 = 'A' then set N_COLUMN3= 'NEW_A';
ELSEIF N_COLUMN1 = 'B' then set N_COLUMN3= 'NEW_B';
END IF;
exception when others then set N_COLUMN3= 'OTHERS'
RETURN N_COLUMN3;
END;
I'm getting error on Exception part.I searched over internet and i'm getting DECLARE type HANDLER FOR SQLEXCEPTION they provide this syntax and mentioned before execution part need to declare this one.i'm not sure what word i need to use in place of type.can anyone help me what is the equaivalent DB2 syntax for exception when others

Answer 1

This depends on where you want to pass the control in your code after the handler invocation.
Look at the handler-declaration description.
Below is a possible example of the function code.
CREATE FUNCTION FUNCTION_NAME
(
IN PARAMETER1 VARCHAR (1)
)
Returns varchar(4000)
BEGIN
declare N_COLUMN1 varchar(1);
declare N_COLUMN2 INT;
declare N_COLUMN3 VARCHAR(2000);
DECLARE EXIT HANDLER FOR SQLEXCEPTION
BEGIN
-- The last statement executed in the function
-- when the handler fires.
-- The control is passed out of the function body
-- since the handler is declared
-- in the main BEGIN END function block.
RETURN 'OTHERS';
END;
SELECT A.COLUMN1,A.COLUMN2
INTO N_COLUMN1,N_COLUMN2
FROM
--TABLE A
(
VALUES
('A', 0)
, ('A', 0)
, ('B', 0)
) A (COLUMN1, COLUMN2)
WHERE A.COLUMN1=PARAMETER1;
IF N_COLUMN1 = 'A' then
set N_COLUMN3 = 'NEW_A';
ELSEIF N_COLUMN1 = 'B' then
set N_COLUMN3 = 'NEW_B';
END IF;
--exception when others then set N_COLUMN3= 'OTHERS'
RETURN N_COLUMN3;
END
SELECT P, FUNCTION_NAME (P) AS F
FROM (VALUES 'A', 'B') T (P)
P
F
A
OTHERS
B
NEW_B
fiddle