Codeigniter：活动记录插入唯一值

Question

I am importing GMail contacts from Google API and just want to persist unique email ids into database. Is it possible to insert unique records using codeigniter's Active Record? Does CodeIgniter provide it out of the box?
If I make the column unique the query throws exception. After digging into documentation I understood that CodeIgniter doesn't provide try catch blocks.

Answer 1

You can create a base model (application/core/MY_Model.php) and implement a save function to insert if new and update if exists. Extend your model from it.

This is an extract from http://thephpcode.com/blog/codeigniter/a-smart-codeigniter-model

public function save($data,$tablename="")
{
if($tablename=="")
{
    $tablename = $this->table;
}
$op = 'update';
$keyExists = FALSE;
$fields = $this->db->field_data($tablename);
foreach ($fields as $field)
{
    if($field->primary_key==1)
    {
        $keyExists = TRUE;
        if(isset($data[$field->name]))
        {
            $this->db->where($field->name, $data[$field->name]);
        }
        else
        {
            $op = 'insert';
        }
    }
}

if($keyExists && $op=='update')
{
    $this->db->set($data);
    $this->db->update($tablename);
    if($this->db->affected_rows()==1)
    {
        return $this->db->affected_rows();
    }
}

$this->db->insert($tablename,$data);

return $this->db->affected_rows();

}