cakephp 3增量记录

Question

我尝试从控制器增加表记录，但失败，我想创建一个添加到购物篮的方法，该方法将插入新产品或更新现有产品的数量。 我也想知道是否有任何书或教程（cakephp网站的教程除外），其中详细介绍了cakephp。 我是cakephp的初学者，似乎很混乱，我们欢迎您提供任何帮助。

调节器

我的代码：

>  function add($id = null,$name = null){
>        
>        $addCart = $this->Cart->newEntity();
> 
>        if($this->request->is('Get')){
>           
>           $data1 = $this->Cart->exists(['productId' => $id]);
>         
>         //if product doesn't exist in table then add it
>           if(!$data1){ 
>             $addCart = $this->Cart->patchEntity($addCart,[
>                                                 'productId' => $id,
>                                                 'name' => $name,
>                                                 'productQty' => 1]
>                                                 );
>             if($this->Cart->save($addCart)){
>               $this->Flash->success(__('The product has been saved.'));
>               return $this->redirect(['controller' => 'users','action' => 'index']);
>             }else{
>               $this->Flash->error(__('The product could not be saved. Please, try again.'));
>             }
> 
>           }else{ //if product already exists in table then update quantity
>             $updateQty = $this->Cart->patchEntity($addCart, [
>                                                ['productQty' => 'productQty+1'],
>                                                'conditions' => ['productId' => $id] //update quantity where the product id matches
>                                                ]);
>            if($this->Cart->save($updateQty)){
>               $this->Flash->success(__('The product already exists.Quantity updated'));
>               return $this->redirect(['controller' => 'users','action' => 'index']);
>            }else{
>               $this->Flash->error(__('The product could not be updated. Please, try again.'));
>            }
>           }//end inner if
> 
>        }//end if
>         }//end function

视图

<button class="btn btn-default">
  <?= $this->Html->link('Add Product',['controller' => 'Cart', 'action' => 'add',2,'gpu'])
      //$this->Html->link('Add Product',['controller' => 'Cart', 'action' => 'index'])
  ?>
</button>

Answer 1

读取当前值，在PHP级别递增并更新表很容易出现竞争状况，相反，请使用表达式添加原始SQL代码段，以在DB级别递增列值

$query = $this->Cart->query();
$result = $query
    ->update()
    ->set(
        $query->newExpr('productQty = productQty + 1')
    )
    ->where([
        'productId' => $id
    ])
    ->execute();

也可以看看

• 食谱>数据库访问和ORM>查询生成器>更新数据
• 食谱>数据库访问和ORM>查询生成器>原始表达式