Queries that include some invalid items in a where clauses will issue warnings when:
-
The where clause has a relational term in which both sides are constants.
-
A conjunct or disjunct or unary negation has only a constant term.
-
The entire where clause is just a constant.
(A constant term is one that is not a select clause, thus does not vary from object to object.)
A message is also output to warn about these situations in those cases where the expression might be indexed (made part of the SQL query to get candidate objects):
-
The keywords
fromset
and
toset
used without a set name.
-
The keywords
from
,
to
, and
relationship
used with a name that should be the name of a relationship type, but it is not.
-
The keyword
attribute
used with a name that should be the name of an attribute type, but it is not.
If you receive such a warning, you should cancel the query evaluation and correct the problem.