16f6c0aecf
Inline adoc files when they are included exactly once. Also fix language tags because this inlining gives us better information on what language the code is written in.
62 lines
1.4 KiB
Plaintext
62 lines
1.4 KiB
Plaintext
== Why is this an issue?
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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.
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Instead, a ``++WHILE++`` loop should be used.
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=== Noncompliant code example
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[source,sql]
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----
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DECLARE
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TYPE fooType IS TABLE OF VARCHAR2(42);
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foo fooType := new fooType('Strawberry', 'Apple', 'Banana');
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BEGIN
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foo.DELETE(2); -- The collection is now sparse
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FOR i IN 1 .. foo.COUNT -- Noncompliant - leads to ORA-01403: no data found
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LOOP
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DBMS_OUTPUT.PUT_LINE(i || ' = ' || foo(i));
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END LOOP;
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END;
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/
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----
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=== Compliant solution
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[source,sql]
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----
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DECLARE
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TYPE fooType IS TABLE OF VARCHAR2(42);
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foo fooType := new fooType('Strawberry', 'Apple', 'Banana');
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i PLS_INTEGER;
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BEGIN
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foo.DELETE(2); -- The collection is now sparse
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i := foo.FIRST;
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WHILE (i IS NOT NULL) -- Compliant - works as expected
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LOOP
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DBMS_OUTPUT.PUT_LINE(i || ' = ' || foo(i));
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i := foo.NEXT(i);
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END LOOP;
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END;
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/
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----
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ifdef::env-github,rspecator-view[]
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'''
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== Implementation Specification
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(visible only on this page)
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=== Message
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Use a "WHILE" loop instead.
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endif::env-github,rspecator-view[]
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