== Why is this an issue?

As soon as a ``++WHEN++`` clause contains too much logic this highly decreases the readability of the overall expression. In such case, the content of the ``++WHEN++`` clause may be extracted into a dedicated function.

=== Noncompliant code example

With a threshold of 5:

[source,sql]
----
SELECT CASE column1
  WHEN 1 THEN
    CASE column2
      WHEN 'a' THEN -- Noncompliant, 7 lines till ELSE
        'x'
      ELSE
        'y'
      END
  ELSE
    42
  END 
FROM table1;
----

=== Compliant solution

[source,sql]
----
SELECT CASE
  WHEN column1 = 1 AND column2 = 'a' THEN
    'x'
  WHEN column1 = 1 THEN
    'y'
  ELSE
    42
  END 
FROM table1;
----

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

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

include::../message.adoc[]

=== Parameters

.max
****
_Integer_

----
10
----

Maximum number of lines of code
****


'''
== Comments And Links
(visible only on this page)

include::../comments-and-links.adoc[]
endif::env-github,rspecator-view[]