Getting the last User ID in Zend Framework - mysql

Question

Using MySQL query browser, I manually made a table called users and input some date in the fields. I set the primary key to id and set it to auto increment. There are 3 rows, the highest id is 3.
I then made the following class in the method directory to call upon the data in the table etc.
class Application_Model_DbTable_User extends Zend_Db_Table_Abstract
{
protected $_name = 'user';
public function getLatestUserId()
{
$id = $this->getAdapter()->lastInsertId();
return $id;
}
}
In the controller I do the following which gets the value generated by the method and lets the view access it:
$usersDbModel = new Application_Model_DbTable_User();
$lastUserId = $usersDbModel->getLatestUserId();
$this->view->lastUserId = $lastUserId;
In the view I then echo it to display it to the user:
echo $this->lastUserId;
However, even though my last id in the users table is 3. It displays 0.
I have also tried:
public function getLatestUserId()
{
$sql = 'SELECT max(id) FROM user';
$query = $this->query($sql);
$result = $query->fetchAll();
return $result;
}
But this just throws out a server error.
What have I done wrong?
Am I missing something?
Is there another way of doing this?

Answer 1

The answer was:
$sql = 'SELECT max(id) FROM user';
$query = $this->getAdapter()->query($sql);
$result = $query->fetchAll();
return $result[0]['max(id)'];

Answer 2

If you queried like "SELECT id FROM USERS SORT BY id DESC LIMIT 0,1"
You would get nothing but the id of the newest user, no?

Answer 3

if you use a select statement like
SELECT max(id) FROM USERS;
If you haven't tried having a function in the controller try something like this.
class IndexController extends Zend_Controller_Action {
public function init() {
}
public function indexAction() {
}
public function getLatestUserId()
{
$bootstrap = $this->getInvokeArg('bootstrap');
$resource = $bootstrap->getPluginResource('db');
$db = $resource->getDbAdapter();
$sqlrequest = "select max(id) as Idmax from user";
$rows = $db->fetchAll($sqlrequest);
foreach ($rows as $row)
echo $maxId = $row['Idmax'];
return $maxId;
}
}
and your bootstrap file would look something like
class Bootstrap extends Zend_Application_Bootstrap_Bootstrap
{
protected function _initConfig()
{
$config = new Zend_Config($this->getOptions());
Zend_Registry::set('config', $config);
return $config;
}
}
Hopefully something like that works, hope it helped

Answer 4

The problem is that Mysql doesn't really support lastInsertId() it will in some cases return the last id of an auto incrementing primary key.
Several solutions have been presented here and most will return the last id of the primary key, which may or may not be what you really need.
This method will also do the same using the select() object.
public function getlastInsertId(){
$select = $this->select();
$select->from($this->_name, "id");
$select->order('id DESC');
$select->limit(0, 1);
$result = $this->fetchAll($select)->current();
return $result->id;
}
I think that over time you may find these kinds of methods unreliable if what you're really after is the last id you inserted. Over time as records are added and deleted the database may or may not fill in vacant id's depending on which database you are currently using and how that database is set up.
In most cases we need the id of the last item inserted very soon after inserting it, usually to update a view script. In this instance I usually just make the whole row object part of the return.
Here is an example of what I mean:
/**this method will save or update a record depending on data present in the array*/
public function saveUser(array $data) {
/**cast data array as std object for convience*/
$dataObject = (object) $data;
/**if id exists as array and has a non null value*/
if (array_key_exists('id', $data) && isset($data['id'])) {
/**find row if updating*/
$row = $this->find($dataObject->id)->current();
} else {
/**create new row*/
$row = $this->createRow();
}
$row->first_name = $dataObject->first_name;
$row->last_name = $dataObject->last_name;
$row->email = $dataObject->email;
/**save or update row*/
$row->save();
/**return the $row you just built or you can return $result = $row->save(); and get*/
/** just the primary key. Save() will throw an exception if table is marked read only*/
return $row;
}