I'm currently working on a symfony 5 project and while trying to insert a name in the database, I received this error : An exception occurred while executing a query: SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'name' cannot be null

The method:

    public function add_category(Request $request, EntityManagerInterface $em) : Response
    {

        $form=$this->createForm(CategoryType::class);
        $form->handleRequest($request);

        if($form->isSubmitted()){

            $category=new Category;
            $em->persist($category);
            $em->flush();
            dump($request);

        }
        $formView=$form->createView();

        return $this->render('admin/category/add_category.html.twig', [
            'formView'=>$formView,

        ]);
    }

The formBuilder :

public function buildForm(FormBuilderInterface $builder, array $options): void
    {
        $builder
            ->add('name', TextType::class,[
                'label'=>'Nom de la catégorie',
                'attr'=>[
                    'class'=>'form-control mb-2',
                    'placeholder'=>'Nom de la catégorie'
                ]
            ]);
    }

The twig form:

{{ form_start(formView) }}
    {{ form_row(formView.name) }}
    <button type="submit" >
        <i ></i>Créer la catégorie
    </button>
    {{ form_end(formView) }}

The property name in the Category Entity:

    /**
     * @ORM\Column(type="string", length=255)
     */
    private $name;

    public function getName(): ?string
    {
        return $this->name;
    }

    public function setName(string $name): self
    {
        $this->name = $name;

        return $this;
    }

CodePudding user response：

It should be like this:

public function add_category(Request $request, EntityManagerInterface $em) : Response
{
    // Create new category here
    $category=new Category();
    // Add $category to createForm method as second argument
    $form=$this->createForm(CategoryType::class, $category);
    $form->handleRequest($request);

    if($form->isSubmitted()){
        // After form is submitted
        // $category will be filled 
        // with data from $form
        $em->persist($category);
        $em->flush();
        dump($request);
    }
    $formView = $form->createView();

    return $this->render('admin/category/add_category.html.twig', [
        'formView'=>$formView,
    ]);
}

You can read more about processing forms from the docs.