Oracle PL/SQL supports various types of LOOP statements, which allow you to execute a sequence of statements multiple times. The different types of loop statements are: LOOP, WHILE-LOOP, FOR-LOOP. Oracle PL/SQL LOOP statements are often used to process data in bulk or to iterate through the elements of a collection or an array.
LOOP
LOOP -- sequence of statements END LOOP;
When using a loop statement, you need to be careful to avoid creating an infinite loop, which is a loop that never exits. An infinite loop will cause your program to run indefinitely and can result in performance issues or may even cause your program to crash.
EXIT
LOOP
v_count := 10;
IF v_count = 10 THEN
EXIT;
END IF;
END LOOP;
To avoid creating an infinite loop, you should always include a exit condition in your loop statement.
The exit condition is a condition that, when met, will cause the loop to exit.
It is also important to note that, when using a loop statement, the order in which the statements in the loop are executed is important. This is because the statements in the loop are executed multiple times and so the order in which they are executed can have an impact on the outcome of your program.
EXIT-WHEN
LOOP
v_count := v_count + 10;
EXIT WHEN v_count = 11;
END LOOP;
Finally, when using a loop statement, you should be aware of the impact that the loop may have on the performance of your program. This is because, as the number of times the loop is executed increases, so will the amount of time that your program takes to run.
FOR-LOOP
FOR counter IN [REVERSE] lower_number..higher_number LOOP -- sequence of statements END LOOP;
In general, you should try to avoid using loop statements if possible. However, there are some situations where they may be necessary or even the best option. If you do need to use a loop statement, it is important to choose the right type of loop and to include an exit condition to avoid creating an infinite loop.
Additionally, you should be aware of the impact that the loop may have on your program’s performance.
WHILE-LOOP
WHILE condition LOOP -- sequence of statements END LOOP;