Views query argument handling

There is an incoherent mode of using query arguments in the handlers/views_handler_filter_string.inc that happens to work on mysql but is not logically correct. I will use the op_contains function as an example but the bug applies to many other functions:

Actually the function looks like this:

function op_contains($field, $upper) {
$this->query->add_where($this->options['group'], "$upper(%s) LIKE $upper('%%%s%%')", $field, $this->value);
}

The fact is that $field is for example "node.title" so it is not an argument but part of the query (a table column)...
This happens to work on mysql because the current implementation of variable binding in the MySQL driver is to
replace values directly in the query... So the final query looks like this:

select * from node where upper(node.title) like '%myval%'

where other implementation like pgsql or oracle will have:

select * from node where upper(:bind1) like '%'||:bind2||'%' args('node.title','myval')

that obviuosly will not return correct values...

the correct implementation should be this (IMUO):

function op_contains($field, $upper) {
$this->query->add_where($this->options['group'], "$upper($field) LIKE $upper('%%%s%%')", $this->value);
}