how to write MySQL queries in cakephp 3 - php

Question

I am trying to do login system in cakephp 3.
Here is the query:
$user_details = $this->User->find('first', ['conditions'=>['email_id'=$email, 'password'=>$password]]);
if(!empty($user_details)){
$this->request->session()->write('user_email'=>$user_details['email_id']);
$this->request->session->write('user_id'=>$user_details['id');
}
Can you tell the differences from cakephp 2 to cakephp 3 about writing queries?

Answer 1

try this query its work fine for you...
$user_details = $this->User->find('first', ['conditions'=>['User.email_id'=$email, 'User.password'=>$password]]);
otherwise you get help from http://book.cakephp.org/3.0/en/controllers/components/authentication.html

Answer 2

For authenticating users you should use the Authentication component. This serves as the best implementation within CakePHP as it automatically binds all the data to the server and request.
public function initialize()
{
parent::initialize();
$this->loadComponent('Auth', [
'loginAction' => [
'controller' => 'Users',
'action' => 'login',
'plugin' => 'Users'
],
'authError' => 'Did you really think you are allowed to see that?',
'authenticate' => [
'Form' => [
'fields' => ['username' => 'email']
]
],
'storage' => 'Session'
]);
}
Please refer to the documentation: http://book.cakephp.org/3.0/en/controllers/components/authentication.html
To answer your original question
Cake 2 uses an automagical function with an array structure for building queries which is quite devious. The query is executed directly on call.
array(
'conditions' => array('Model.field' => $thisValue), //array of conditions
'recursive' => 1, //int
//array of field names
'fields' => array('Model.field1', 'DISTINCT Model.field2'),
//string or array defining order
'order' => array('Model.created', 'Model.field3 DESC'),
'group' => array('Model.field'), //fields to GROUP BY
'limit' => n, //int
'page' => n, //int
'offset' => n, //int
'callbacks' => true //other possible values are false, 'before', 'after'
)
http://book.cakephp.org/2.0/en/models/retrieving-your-data.html
Within Cake 3 the query is built using a query builder object. This modifies the SQL on every subsequent call. It is only executed after you call it to.
$query = $articles->find('all')
->where(['Articles.created >' => new DateTime('-10 days')])
->contain(['Comments', 'Authors'])
->limit(10);
Here the an object is manipulated with a referenced SQL on every call (where, contain, limit).
The query is executed after you apply execute(), first(), toArray() etc, where toArray() returns the data set as an array and others as an object.
Further reading: http://book.cakephp.org/3.0/en/orm/retrieving-data-and-resultsets.html