laravel：Eloquent的例子将数据插入数据库

好的，我已经重读了你的问题，我认为你有一些地方错了，所以我不想在主要帖子上留下任何进一步的 comments ，我想我可以试着回答一下，所以就这样吧.

First off, your relationship is the wrong type and the wrong way around. As I understand it (and as I implement these things in my own work) a product belongs to a brand - a brand may have multiple products, but a product can only have one brand. So first your DB schema - you mention you have a products table with the normal columns and then the foreign key brand_id. So far so good: this is consistent with the way I interpret the relationship.

然而，你接着向我们展示你的模型.你的产品型号是hasOne品牌，但实际上它属于一个品牌.你也不需要定义关系的反面——你需要双方共同努力才能让Laravel很好地工作.除此之外，你的命名有点不正常——它可能会起作用，但如果我们遵循拉威尔的惯例，我们会得到以下结果:

In the products model: Product.php

class Product extends Eloquent
{
    public function brand()
    {
        return $this->belongsTo('Brand');
    }
}

现在是brands型号:Brand.php

class Brand extends Eloquent
{
    public function products()
    {
        return $this->hasMany('Product');
    }
}

好的，到目前为止一切都很好.您会注意到各种约定:

1. Table names are plural (products, brands)
2. 外键使用单数(brand_id)
3. Model names are singular and StudlyCase (so Product for a table products, Brand for table brands)
4. 只要遵循Laravel约定(即表名是模型类名的复数Snake_Case版本)，就不必指定$table属性
5. 你应该以两种方式定义关系(每个模型中一个，belongsTo的倒数是hasMany，还有hasOne/belongsTo和belongsToMany/belongsToMany对)
6. 检索关系的方法的名称是合理的-如果您期望一个结果，则将其设为单数(Product中为brand)，如果您希望多个结果中为复数(Brand中为products)，则将其设为单数
7. Use the model classnames in your relationship definitions ($this->hasMany('Brand') not $this->hasMany('brands') or any other variation

如果你坚持这些规则，你的模型可以非常简洁，但非常强大.

Now, as for how you actually define real data, I have a feeling the code you posted may work fine (it really depends on how clever Laravel is behind the scenes), but as I suggested in my first comment, I'd ensure that I saved the $brand before calling associate(), just so that Laravel doesn't get lost working out what to do. As such I'd go for:

// create new brand and save it
$brand = new Brand;
$brand->name = "Brand 1";
$brand->save();

// create new product and save it
$product = new Product;
$product->name = "Product 1";
$product->description = "Description 1";
$product->brand()->associate($brand);
$product->save();

这样，你就知道你在数据库中有一个品牌，在你开始在关系中使用它之前，它的ID已经定义好了.

你也可以用相反的方式定义这种关系，这样做对大脑的伤害可能更小:

// create new product and save it
$product = new Product;
$product->name = "Product 1";
$product->description = "Description 1";
$product->save();

// create new brand and save it
$brand = new Brand;
$brand->name = "Brand 1";
$brand->save();

// now add the product to the brand's list of products it owns
$brand->products()->save($product);

在最后一行之后，你不需要在任何一个模型上调用save()，因为它会自动获取$brand的id值，将其放入$product的brand_id字段，然后保存$product.

有关更多信息，请参阅有关如何处理此关系的文档插入:http://laravel.com/docs/eloquent#one-to-many

Anyway, hopefully this post clears up a good amount of what was wrong with your code. As I said above, these are conventions, and you can go against them, but to do so you have to start putting extra code in, and it can be quite unreadable for other developers. I say if you pick a given framework, you may as well follow its conventions.