Question

I have the following…

IF CONDITION1  THEN

        -- SELECT  STATEMENT MIGHT RETURN DATA

         IF CONDITION2 THEN

                -- SELECT COUNT

             IF CONDITION3 THEN



                    INSERT INTO TABLE
                            (
                            --- 
                            )
                    VALUES  (
                            ---
                            );


            End IF;


    END IF;


 END IF;


EXCEPTION
   WHEN NO_DATA_FOUND THEN
 RETURN;

END of Trigger

Is this a correct way of handling exception for select statement inside CONDITION1?

Answer 1

PL/SQL has no way to return to the site of the error, so you need to create a block around the portion you want to ignore specific errors:

IF CONDITION1  THEN
         BEGIN
         -- SELECT  STATEMENT MIGHT RETURN DATA
         EXCEPTION
             WHEN NO_DATA_FOUND THEN
                 NULL;
         END;
         IF CONDITION2 THEN
                -- SELECT COUNT
             IF CONDITION3 THEN
                    INSERT INTO TABLE
                            (
                            --- 
                            )
                    VALUES  (
                            ---
                            );
            End IF;
    END IF;
 END IF;
END TRIGGER_NAME;

An alternative is to use an explicit cursor, which does not return an error when it is empty:

DECLARE
   CURSOR cur_sample is select dummy from dual where 1=0;
   v_dummy dual.dummy%type;
BEGIN
   IF CONDITION1  THEN
         open cur_sample;
         fetch cur_sample into v_dummy;
         close cur_sample;
         IF CONDITION2 THEN
                -- SELECT COUNT
             IF CONDITION3 THEN
                    INSERT INTO TABLE
                            (
                            --- 
                            )
                    VALUES  (
                            ---
                            );
            End IF;
       END IF;
    END IF;
END;