+=head2 sql C<[ $dbh, ] $query, @bind_values>
+
+Executes an SQL query using the optional bind values. If the first
+parameter is a database handle then that database handle is used;
+otherwise the handle returned by L<SL::Form/get_standard_dbh> is used.
+
+If the query is a C<SELECT> then the result is filtered through
+L<ptab()>. Otherwise the result of C<$dbh->do($query, undef, @bind_values)>
+is returned.
+
+Example usage:
+
+ sql(qq|SELECT * FROM employee|);
+ sql(SL::DB::Employee->new->db->dbh,
+ qq|UPDATE employee SET notes = ? WHERE login = ?|,
+ 'This guy is evil!', 'demo');
+