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.
76 lines
1.5 KiB
Plaintext
76 lines
1.5 KiB
Plaintext
== Why is this an issue?
|
|
|
|
``++DECODE++`` is an old function that has been replaced by the easier to understand and more common ``++CASE++``. Unlike ``++DECODE++``, ``++CASE++`` may also be used directly within PL/SQL.
|
|
|
|
|
|
=== Noncompliant code example
|
|
|
|
[source,sql]
|
|
----
|
|
SET SERVEROUTPUT ON
|
|
|
|
DECLARE
|
|
operand CHAR(1) := 'B';
|
|
l_result PLS_INTEGER;
|
|
BEGIN
|
|
-- Noncompliant
|
|
SELECT DECODE(operand, 'A', 1
|
|
, 'B', 2
|
|
, 'C', 3
|
|
, 'D', 4
|
|
, 'E', 5
|
|
, 'F', 6
|
|
, 7)
|
|
INTO l_result
|
|
FROM dual;
|
|
|
|
DBMS_OUTPUT.PUT_LINE('l_result = ' || l_result); -- 2
|
|
END;
|
|
/
|
|
----
|
|
|
|
|
|
=== Compliant solution
|
|
|
|
[source,sql]
|
|
----
|
|
SET SERVEROUTPUT ON
|
|
|
|
DECLARE
|
|
operand CHAR(1) := 'B';
|
|
l_result PLS_INTEGER;
|
|
BEGIN
|
|
|
|
l_result := CASE operand
|
|
WHEN 'A' THEN 1
|
|
WHEN 'B' THEN 2
|
|
WHEN 'C' THEN 3
|
|
WHEN 'D' THEN 4
|
|
WHEN 'E' THEN 5
|
|
WHEN 'F' THEN 6
|
|
ELSE 7
|
|
END;
|
|
|
|
DBMS_OUTPUT.PUT_LINE('l_result = ' || l_result); -- 2
|
|
END;
|
|
/
|
|
----
|
|
|
|
|
|
=== Exceptions
|
|
|
|
No issue is raised when ``++DECODE++`` contains only one case (i.e. only one ``++search++`` and one ``++result++`` components) because using ``++CASE++`` would make the code less readable in this scenario.
|
|
|
|
ifdef::env-github,rspecator-view[]
|
|
|
|
'''
|
|
== Implementation Specification
|
|
(visible only on this page)
|
|
|
|
=== Message
|
|
|
|
Replace this use of "DECODE" with "CASE".
|
|
|
|
|
|
endif::env-github,rspecator-view[]
|