rspec/rules/S4062/plsql/rule.adoc

== Why is this an issue?

Oracle's ``++ROWNUM++`` is a pseudo column that numbers the rows in a result set. Unfortunately, it numbers the rows in the set _before_ ordering is applied. So combining the two in the same query won't get you the results you expect. Instead, you should move your selection and ordering into a subquery, and use ``++ROWNUM++`` only on the outer query.


=== Noncompliant code example

[source,sql]
----
SELECT fname, lname, deptId
FROM employee
WHERE rownum <= 10
ORDER BY salary  -- Noncompliant
----


=== Compliant solution

[source,sql]
----
SELECT * 
FROM ( SELECT fname, lname, deptId
    FROM employee
    ORDER BY salary
  )
WHERE rownum <= 10
----


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