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
1.4 KiB
Plaintext
76 lines
1.4 KiB
Plaintext
== Why is this an issue?
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A ``++CASE++`` and a chain of ``++IF++``/``++ELSE IF++`` 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 @x = 1
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PRINT 'A'
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ELSE IF @x = 2
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PRINT 'B'
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ELSE IF @x = 1 -- Noncompliant
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PRINT 'C'
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SELECT
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CASE col1
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WHEN 1
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THEN 'A'
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WHEN 2
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THEN 'B'
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WHEN 1 -- Noncompliant
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THEN 'C'
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ELSE 'D'
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END
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FROM table1
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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 @x = 1
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PRINT 'A'
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ELSE IF @x = 2
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PRINT 'B'
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ELSE IF @x = 3
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PRINT 'C'
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SELECT
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CASE col1
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WHEN 1
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THEN 'A'
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WHEN 2
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THEN 'B'
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WHEN 3
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THEN 'C'
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ELSE 'D'
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END
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FROM table1
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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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This condition duplicates the one on line n.
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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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