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.
42 lines
975 B
Plaintext
42 lines
975 B
Plaintext
== Why is this an issue?
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A ``++CROSS JOIN++`` query will return all records where each row from the first table is combined with each row from the second table. This means that such a query returns the Cartesian product of the sets of rows from the joined tables, which is why it is also know as "Cartesian product query".
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Such a query can return a huge amount of data, and therefore should be used only with great caution and only when really needed.
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=== Noncompliant code example
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[source,sql]
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----
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BEGIN
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-- Standard ANSI syntax
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SELECT *
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INTO employeeArray
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FROM employee CROSS JOIN department; -- Noncompliant; explicit cross join
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END;
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/
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BEGIN
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-- Old syntax
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SELECT *
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INTO employeeArray
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FROM employee, department; -- Noncompliant; also a cross join
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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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Remove this "CROSS JOIN" query
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endif::env-github,rspecator-view[]
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