MYSQL Functions

[eluser]vtafsar[/eluser]
Yes. I have already read active record class manual.
What I need is to run a query like:

UPDATE table_name SET field_name2=CONCAT(field_name2, "Some content") WHERE field_name1=1;

I tried the following code,

==================================================================
$this->db->where(field_name1, 1);
$this->db->update(table_name, array('field_name2'=> "CONCAT(field_name2, \"Some content\")"));
==================================================================

but it is not updating the field like what I am looking for.
Hope now you understand what is my question.

Thank You