如何使用django-mptt模型进行bulk_create？

如何解决如何使用django-mptt模型进行bulk_create？

我需要在django-mptt模型上使用 bulk_create ，但出现错误：

django.db.utils.IntegrityError：“ lft”列中的空值违反了非空约束 详细信息：失败行包含（2，Magic，null，null，null，null，null，null，1）。

如何在不进行硬编码lft，rght和tree_id的情况下批量创建django-mptt模型？

MRE

models.py：

from mptt.models import MPTTModel,TreeForeignKey

class Category(MPTTModel):
    parent = TreeForeignKey('self',on_delete=models.CASCADE,blank=True,null=True,related_name='children',)
    name = models.CharField(max_length=255)
    tcgplayer_category = models.ForeignKey('tcgplayer.TcgCategory',on_delete=models.PROTECT,null=True)

    class Meta:
        unique_together = (
            ('parent','name'),)

    def __str__(self):
        return self.name

class TcgCategory(models.Model):
    id = models.PositiveSmallIntegerField(primary_key=True)
    name = models.CharField(max_length=255)

class CategoryGroup(models.Model):
    id = models.IntegerField(primary_key=True)
    category = models.ForeignKey('tcgplayer.TcgCategory',on_delete=models.CASCADE)

装置/category.json：

[{
    "model": "tcgplayer.tcgcategory","pk": 1,"fields": {
      "name": "Magic",}
},{
    "model": "tcgplayer.categorygroup","fields": {
      "category": 1,"name": "10th Edition","pk": 2,"name": "7th Edition",}
}]

tasks.py：

def convert_categories(category_ids):
    root_categories = TcgCategory.objects.filter(id__in=category_ids)
    category_parents = Category.objects.bulk_create([ # error is thrown here
        Category(
            tcgplayer_category_id=model['id'],name=model['name'],)
        for model in root_categories.values('id','name')
    ])
    for parent in category_parents:
        category_groups = CategoryGroup.objects.filter(category_id=parent.tcgplayer_category_id)
        category_models.extend([
            Category(
                tcgplayer_category_id=model['id'],parent=parent,)
            for model in category_groups.values('id','name')
        ])
    Category.objects.bulk_create(category_models)

解决方法

回复晚了，但硬编码 > Illuminate\Foundation\ComposerScripts::postAutoloadDump > @php artisan package:discover --ansi Illuminate\Contracts\Container\BindingResolutionException Target class [company\mypackage\ApplyController] does not exist. at vendor/laravel/framework/src/Illuminate/Container/Container.php:835 831▕ 832▕ try { 833▕ $reflector = new ReflectionClass($concrete); 834▕ } catch (ReflectionException $e) { ➜ 835▕ throw new BindingResolutionException("Target class [$concrete] does not exist.",$e); 836▕ } 837▕ 838▕ // If the type is not instantiable,the developer is attempting to resolve 839▕ // an abstract type such as an Interface or Abstract Class and there is +6 vendor frames 7 /Users/user/Sites/laravel-packages/mypackage/src/MyPackageServiceProvider.php:18 Illuminate\Foundation\Application::make("company\mypackage\ApplyController") +7 vendor frames 15 artisan:37 Illuminate\Foundation\Console\Kernel::handle(Object(Symfony\Component\Console\Input\ArgvInput),Object(Symfony\Component\Console\Output\ConsoleOutput)) Script @php artisan package:discover --ansi handling the post-autoload-dump event returned with error code 1 、lft 和 rght 并没有错。在模型创建后添加 MPTTModel 类时实际上是 recommended，只要在创建后运行 tree_id。

rebuild

您可能需要将模型稍微调整为 add some kind of ordering

for parent in category_parents:
    category_groups = CategoryGroup.objects.filter(category_id=parent.tcgplayer_category_id)
    category_models.extend([
        Category(
            tcgplayer_category_id=model['id'],name=model['name'],parent=parent,lft=0,rght=0,tree_id=0
        )
        for model in category_groups.values('id','name')
    ])
Category.objects.bulk_create(category_models)
Category.objects.rebuild()