Codeigniter: Active Records Insert Unique values - php

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

your email field have to be unique in your table indexes.
$query_string = $this->db->insert_string('table', $data);
$query_string = str_replace('INSERT INTO', 'INSERT IGNORE INTO', $query_string);
$req = $this->db->query($query_string);
if($req->affected_rows() == 1) {
//data inserted
} else {
//email exists already
}
If you use the IGNORE keyword, errors that occur while executing the
INSERT statement are treated as warnings instead. For example, without
IGNORE, a row that duplicates an existing UNIQUE index or PRIMARY KEY
value in the table causes a duplicate-key error and the statement is
aborted. With IGNORE, the row still is not inserted, but no error is
issued. Data conversions that would trigger errors abort the statement
if IGNORE is not specified. With IGNORE, invalid values are adjusted
to the closest values and inserted; warnings are produced but the
statement does not abort.
MySQL INSERT syntax
CI Database Helper

Answer 2

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();
}

Answer 3

If your data comes from a from, CI provides a form_validation class that can validate your form on the server side.By form_validation has a rule called is_unique its checks if the given value is already exist on the database or not. you can see a complete and clear explanation here
Or, you can check it manually before inserting your email in that unqiue column.
$this->db->select('email');
$this->db->where(array('email'=>$email));
$query = $this->db->get('yourtable');
if($query->num_rows() > 0){
// the query returned data, so the email already exist.
}else{
// the email not exists, so you can insert it.
}