To update a record in database, we first need to get hold of a table using TableRegistry class. We can fetch the instance out of registry using the get() method. The get() method will take the name of the database table as an argument. Now, this new instance is used to get particular record that we want to update.

Call the get() method with this new instance, and pass the primary key to find a record, which will be saved in another instance. Use this instance, to set new values that you want to update and then, finally call the save() method with the TableRegistry class’s instance to update record.

Example

Make changes in the config/routes.php file as shown in the following code.

config/routes.php

<?php
use CakeHttpMiddlewareCsrfProtectionMiddleware;
use CakeRoutingRouteDashedRoute;
use CakeRoutingRouteBuilder;
$routes->setRouteClass(DashedRoute::class);
$routes->scope(''/'', function (RouteBuilder $builder) {
   $builder->registerMiddleware(''csrf'', new CsrfProtectionMiddleware([
      ''httpOnly'' => true,
   ]));
   $builder->applyMiddleware(''csrf'');
   //$builder->connect(''/pages'',[''controller''=>''Pages'',''action''=>''display'', ''home'']);
   $builder->connect(''/users/edit'', [''controller'' => ''Users'', ''action'' => ''edit'']);
   $builder->fallbacks();
});

Create a UsersController.php file at src/Controller/UsersController.php. Copy the following code in the controller file.

src/controller/UsersController.php

<?php
   namespace AppController;
   use AppControllerAppController;
   use CakeORMTableRegistry;
   use CakeDatasourceConnectionManager;
   class UsersController extends AppController{
      public function index(){
         $users = TableRegistry::get(''users'');
         $query = $users->find();
         $this->set(''results'',$query);
      }
      public function edit($id){
         if($this->request->is(''post'')){
            $username = $this->request->getData(''username'');
            $password = $this->request->getData(''password'');
            $users_table = TableRegistry::get(''users'');
            $users = $users_table->get($id);
            $users->username = $username;
            $users->password = $password;
            if($users_table->save($users))
            echo "User is udpated";
            $this->setAction(''index'');
         } else {
            $users_table = TableRegistry::get(''users'')->find();
            $users = $users_table->where([''id''=>$id])->first();
            $this->set(''username'',$users->username);
            $this->set(''password'',$users->password);
            $this->set(''id'',$id);
         }
      }
   }
?>

Create a directory Users at src/Template, ignore if already created, and under that directory create a view called index.php. Copy the following code in that file.

src/Template/Users/index.php

<a href="add">Add User</a>
<table>
   <tr>
   <td>ID</td>
   <td>Username</td>
   <td>Password</td>
   <td>Edit</td>
   <td>Delete</td>
   </tr>
   <?php
      foreach ($results as $row):
      echo "<tr><td>".$row->id."</td>";
      echo "<td>".$row->username."</td>";
      echo "<td>".$row->password."</td>";
      echo "<td><a href=''".$this->Url->build(["controller" => "Users","action" => "edit",$row->id])."''>Edit</a></td>";
      echo "<td><a href=''".$this->Url->build(["controller" => "Users","action" => "delete",$row->id])."''>Delete</a></td></tr>";
      endforeach;
   ?>
</table>

Create another View file under the Users directory called edit.php and copy the following code in it.

src/Template/Users/edit.php

<?php
   echo $this->Form->create(NULL,array(''url''=>''/users/edit/''.$id));
   echo $this->Form->control(''username'',[''value''=>$username]);
   echo $this->Form->control(''password'',[''value''=>$password]);
   echo $this->Form->button(''Submit'');
   echo $this->Form->end();
?>

Execute the above example by visiting the following URL and click on Edit link to edit record.

http://localhost/cakephp4/users

Output

After visiting the above URL, it will display the records in users table as shown below −

Click on Edit button and it will display you following screen −

Now, we will update the name Virat to Virat123 and submit the details. The next screen displayed will be as follows −