65 lines
1.4 KiB
Plaintext
65 lines
1.4 KiB
Plaintext
== Why is this an issue?
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A ``++CASE++`` and a chain of ``++IF++``/``++ELSIF++`` statements is evaluated from top to bottom. At most, only one branch will be executed: the first one with a condition that evaluates to ``++true++``.
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Therefore, duplicating a condition automatically leads to dead code. Usually, this is due to a copy/paste error. At best, it's simply dead code and at worst, it's a bug that is likely to induce further bugs as the code is maintained, and obviously it could lead to unexpected behavior.
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=== Noncompliant code example
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[source,sql]
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----
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IF param == 1 THEN
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x := 'A';
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ELSIF param == 2 THEN
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x := 'B';
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ELSIF param == 1 THEN -- Noncompliant, for sure this is a bug
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x := 'C';
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END IF;
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result := CASE param
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WHEN 1 THEN 'A'
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WHEN 2 THEN 'B'
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WHEN 1 THEN 'C' -- Noncompliant
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ELSE 'D'
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END;
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----
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=== Compliant solution
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[source,sql]
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----
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IF param == 1 THEN
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result := 'A';
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ELSIF param == 2 THEN
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result := 'B';
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ELSIF param == 3 THEN
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result := 'C';
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END IF;
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result := CASE param
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WHEN 1 THEN 'A'
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WHEN 2 THEN 'B'
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WHEN 3 THEN 'C'
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ELSE 'D'
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END;
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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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include::../message.adoc[]
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include::../highlighting.adoc[]
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'''
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== Comments And Links
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(visible only on this page)
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include::../comments-and-links.adoc[]
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endif::env-github,rspecator-view[]
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