Codeigniter how to map a class sent to a model - php

Question

I have a SectorModel with this function:
public function update(Sector $sector) {
$this->db->where('sector_id', $sector->getScetor_id());
return $this->db->update(_SECTOR_, $sector);
}
There are times that I’ll change only the name of the Sector object:
$Sector = new Sector();
$Sector->setSector_name = 'test';
$this->SectorModel->update($Sector);
The generated select looks like:
UPDATE realestate_sector SET sector_name = 'teste', sector_description = NULL
It will update but will set all other properties to NULL because it was not set on my object.
Right now, I have to fill the whole object before sending it.
Is there a way to map the Sector class and update only what was sent on the object?
Thanks in advance for any help.
Sorry for any typos, my English is not good =)

Answer 1

Just loop through all your object's properites and then if any is NULL just drop it with unset.
Here is your model's method edited to achieve that:
public function update(Sector $sector)
{
foreach($sector as $k=>$v)
{
if($v === NULL)
unset($sector->$k)
}
$this->db->where('sector_id', $sector->getScetor_id());
return $this->db->update(_SECTOR_, $sector);
}
Here you can find some info about iterating objects in PHP

Answer 2

The easiest to do this would be to rather use a array - docs here http://codeigniter.com/user_guide/database/active_record.html#update - you just create a array of all the columns with their values that you want to update and perform a $this->db->update('mytable', array('name' => 'test'), array('id' => $id)); call. This will only update the columns you specified in the First array. With the second array acting as your WHERE expression.
The only reason I can think of as to why your other values are being set to NULL is because in your example you create a new instance of the class and the other values must either have been set to nothing or are set to NULL. It would (If this is the case) be better to get a record from the table and then change and values on the populated record and pass that to the function to update.
Hope that helps.