my $interval = "now() - interval '12 hours'";
->search({last_attempt => { '<' => \$interval } })
+=item .. search with an SQL function on the left hand side?
+
+To use an SQL function on the left hand side of a comparison:
+
+ ->search({}, { where => \'YEAR(date_of_birth)=1979' });
+
+=begin hidden
+
+(When the bind arg ordering bug is fixed, the previous example can be
+replaced with the following.)
+
+ ->search({}, { where => \'YEAR(date_of_birth)=?', bind => [ 1979 ] });
+
+=end hidden
+
+Or, if you have quoting off:
+
+ ->search({ 'YEAR(date_of_birth' => 1979 });
+
=item .. find more help on constructing searches?
Behind the scenes, DBIx::Class uses L<SQL::Abstract> to help construct
search again or relationship accessors. The SQL query is only run when
you ask the resultset for an actual row object.
+=item How do I deal with tables that lack a primary key?
+
+If your table lacks a primary key, DBIx::Class can't work out which row
+it should operate on, for example to delete or update. However, a
+UNIQUE constraint on one or more columns allows DBIx::Class to uniquely
+identify the row, so you can tell L<DBIx::Class::ResultSource> these
+columns act as a primary key, even if they don't from the database's
+point of view:
+
+ $resultset->set_primary_key(@column);
+
=back
=head2 Notes for CDBI users