Callback column, left outer join

Hello..

can i use callback column function for left outer join ?

how can i use this?

can anyone give example code for this?

for example,

i have 2 tables, table X and Y

X have field A,B,C
Y have field E,B,F

Controller :

...
$crud->set_table('X');
...
$crud->columns('A','B','C','N');
...
$crud->callback_column('N',array(this,'_cb_N'));
...
$output = $crud->render();

function _cb_N($value, $row);
{
...
}

i want to this in callback column:
SELECT *
FROM X LEFT OUTER JOIN Y
ON X.B = Y.B;

i want to column N display field B from table Y

pleaseeee help me..

Callback column, left outer join

Alfandi Nurulmukhlis