Query by the value of a non-existent column using a standard ANSI join, and you'll get an error. Do the same thing in a sub-query, and you'll silently get the wrong result because the condition will effectively be ignored.


== Noncompliant Code Example

----
CREATE TABLE rule (
id integer(10),
.... );

CREATE TABLE issue (
id integer(10),
rule_id integer(10),
... );

SELECT id, status
FROM issue
WHERE rule_id in (
  SELECT rule_id   -- Noncompliant. Condition ignored and all issues selected
  FROM rule
  WHERE ...
)
----

