The ``++FOR++`` loop at first seems like a convenient way of iterating over the elements of a collection, but doing so will raise a ``++VALUE_ERROR++`` exception if the collection is empty. Looping instead from 1 to ``++COUNT++`` doesn't work either if the collection is sparse; that leads to a ``++ORA-01403: no data found++`` error.
Instead, a ``++WHILE++`` loop should be used.
== Noncompliant Code Example
----
DECLARE
TYPE fooType IS TABLE OF VARCHAR2(42);
foo fooType := new fooType('Strawberry', 'Apple', 'Banana');
BEGIN
foo.DELETE(2); -- The collection is now sparse
FOR i IN 1 .. foo.COUNT -- Noncompliant - leads to ORA-01403: no data found
LOOP
DBMS_OUTPUT.PUT_LINE(i || ' = ' || foo(i));
END LOOP;
END;
/
----
== Compliant Solution
----
DECLARE
TYPE fooType IS TABLE OF VARCHAR2(42);
foo fooType := new fooType('Strawberry', 'Apple', 'Banana');
i PLS_INTEGER;
BEGIN
foo.DELETE(2); -- The collection is now sparse
i := foo.FIRST;
WHILE (i IS NOT NULL) -- Compliant - works as expected
