GOTO, RETURN, EXIT in Oracle

1. GOTO, mainly used for jump, but will disrupt our program logic. It is generally not used. It can implement the RETURN and EXIT functions.

2. RETURN: RETURN to the end of the program and end the program.

3. EXIT, mainly used to EXIT the current loop, which is equivalent to break in java.

4. You can use custom exception methods to implement the continue function in java.

Comparison between them

1. -- The GOTO here is equivalent to the following EXIT usage
2. BEGIN
3. FOR I IN1..2LOOP
4. IF I =2THEN
5. GOTO label;
6. End if;
7. Dbms_output.put_line ('I ='| I );
9. End loop;
10. <Label>
11. Dbms_output.put_line ('The last ...');
12. END;
13. /
14. I =1
15. The last...
16. PL/SQL procedure successfully completed.
17. BEGIN
18. FOR I IN1..2LOOP
19. IF I =2THEN
20. -- GOTO label;
21. EXIT;
22. End if;
23. Dbms_output.put_line ('I ='| I );
25. End loop;
26. <Label>
27. Dbms_output.put_line ('The last ...');
28. END;
29. /
30. I =1
31. The last...
32. PL/SQL procedure successfully completed.
33. BEGIN
34. FOR I IN1..2LOOP
35. IF I =2THEN
36. -- GOTO label;
37. -- EXIT;
38. RETURN;
39. End if;
40. Dbms_output.put_line ('I ='| I );
41. End loop;
42. <Label>
43. Dbms_output.put_line ('The last ...');
44. END;
45. /
46. I =1
47. PL/SQL procedure successfully completed.
48. -- The following is equivalent to the above RETURN
49. BEGIN
50. FOR I IN1..2LOOP
51. IF I =2THEN
52. GOTO label;
53. -- EXIT;
54. -- RETURN;
55. End if;
56. Dbms_output.put_line ('I ='| I );
57. End loop;
58. Dbms_output.put_line ('The last ...');
59. <Label>
60. NULL; -- This NULL cannot be omitted. <label> it cannot be earlier than END; end loop;
61. END;
62. /
63. I =1
64. PL/SQL procedure successfully completed.

Customize exceptions to implement the continue Function

1. DECLARE
2. E_My_Exception EXCEPTION;
3. -- PRAGMA EXCEPTION_INIT (e_My_Exception ,-1401);
4. BEGIN
5. FOR I IN1..2LOOP
6. BEGIN
7. IF I =2THEN
8. RAISE e_My_Exception;
9. End if;
10. Dbms_output.put_line ('I ='| I );
11. EXCEPTION
12. WHEN e_My_Exception THEN
13. NULL;
14. END;
15. End loop;
16. Dbms_output.put_line ('The last ...');
17. END;
18. /