rspec/rules/S2472/plsql/rule.adoc

== Why is this an issue?

Oracle supports at most 1000 items in a SQL query's ``++IN++`` clause. When more items are given, the exception ``++ORA-01795 maximum number of expressions in a list is 1000++`` is raised. Thus, ``++IN++`` clauses are not as scalable as joins.


=== Noncompliant code example

[source,sql]
----
BEGIN
  SELECT *
  INTO result
  FROM my_table
  WHERE col1 IN (1, 2, 3, ..., 1001);       -- Noncompliant - raises ORA-01795
END;
/
----


=== Compliant solution

[source,sql]
----
BEGIN
  SELECT my_table.*
  INTO result
  FROM my_table
  JOIN new_in_table
  WHERE my_table.col1 = new_in_table.value; -- Compliant
END;
/
----

ifdef::env-github,rspecator-view[]

'''
== Implementation Specification
(visible only on this page)

=== Message

Refactor this query to use a "JOIN" instead.


=== Parameters

.maximumNumberOfItems
****

----
50
----

Maximum number of items allowed
****


endif::env-github,rspecator-view[]