How can I intercept database requests error?

[eluser]FordEscort[/eluser]
I have just started working with Code Igniter a while and I think it's very interesting.
I'm facing a problem with handling errors.
When running requests that produce database errors (duplicate entry violation for example), the script is exiting and displays the error.
I want to do something like this :

Code:

if ($this->db->update('MyTable', $arrCol))
{
    return true;
}
else
{
    return false;
}

So that the script is not stopped.
Is this possible?;

Thanks.