CODEWITHSUNDEEP
sqloracle-databaseplsqldatabase-cursor
codeObserver
codeObserver

Reputation: 6647

plsql/cursors handle exception and return back to the execution flow

I am trying to execute a cursor and want it to complete the loop even if there is some exception.

What I trying to do is "catch" all the exception and probably log something or do nothing and then return back to the flow . Here is how the code looks like:

 FOR line IN my_cursor
 LOOP
 begin
        
    if<condition> then
      GOTO pass; 
    else     
     <<do_something>>
     exception
       when others then
        sys.dbms_output.put_line('say something');       
    end if;  

    <<pass>> null;
 end
 END LOOP;

The script doesn't compile.

There is probably some syntax error with the exception, but I am also not aware of semantics very well. Like I am not sure if you can return back to execution flow after handling an exception.

p.s: The DB is 10g and there is not CONTINUE in it. Hence using GOTO.

Upvotes: 8

Views: 37924

Answers (3)

user3513976
user3513976

Reputation: 1

 BEGIN 
 FOR Line in My_Cursor LOOP
    IF condition THEN
 BEGIN
    do something...
 END;
    ELSE 
 BEGIN
    do something...
 END;
    END IF;
 END LOOP;
 EXCEPTION
 WHEN OTHERS THEN
 DBMS_OUTPUT.PUT_LINE('say something');
 END;

Upvotes: 0

Ian Carpenter
Ian Carpenter

Reputation: 8626

Put the code that you want to execute within the loop in it's own block and then you can use that blocks exception section to handle any problems during the loop iteration.

Once the exception for that iteration is handled, the next loop iteration will start

e.g.:

for line in my_cursor
loop
   begin    
      <<do_something>>
   exception
      <<do_exception_processing>>        
   end;
end loop;

To illustrate this further, in the example below, I have declared a local variable of type exception. I am looping through numbers 1 to 10, during the second loop iteration, the if statement is true and processing passes to the exception handler. Once the exception is handled, the next iteration of the loop begins. 

begin

   for i in 1 .. 10 
   loop

      declare

         my_exception exception;

      begin

         if i = 2
         then

            -- if you need to do some processing then you would enter it
            -- here and then when you want to enter the exception section 
            -- you would add the line below 

            raise my_exception;

         end if;

      exception
         when my_exception then
            dbms_output.put_line('in exception section');

      end;

   end loop;

end;

Upvotes: 17

Adam Musch
Adam Musch

Reputation: 13583

FOR line IN my_cursor  
LOOP
  if not some_condition then
    begin
      do_something;
    exception     
      when others then log_my_error(); -- this should be something that uses
                                       -- an autonomous transaction
    end;
  end if;
END LOOP;

Upvotes: 7

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