php - Laravel：使用 Eloquent 加入查询
问题描述
我有五个表，我需要从中获取数据。
post,product,categories,attributes,post_attribute
我的模型中有一个查询，它收集一个产品的所有帖子，它包含类别和属性详细信息。询问 ：
Post::with(['product.categories.attributes'])->whereStatus("Active")->get();
回复：
"PostDetails": [
{
"id": 153,
"user_id": 3,
"product_id": 1,
"demand_or_supply": "Demand",
"description": "This is a post description three",
"image_one": null,
"image_two": null,
"image_three": null,
"image_four": null,
"status": "Active",
"created_at": "2018-05-07 09:51:08",
"updated_at": "2018-05-07 09:51:08",
"product": {
"id": 1,
"title": "Diamond",
"icon": null,
"status": "Active",
"created_at": "2018-04-27 18:46:28",
"updated_at": "2018-04-27 18:46:28",
"categories": [
{
"id": 1,
"product_id": 1,
"title": "Shape",
"status": "Active",
"sort_order": 1,
"created_at": "2018-04-27 18:46:28",
"updated_at": "2018-04-27 18:46:28",
"attributes": [
{
"id": 1,
"product_id": 1,
"category_id": 1,
"parent_id": null,
"title": "Round",
"status": "Active",
"sort_order": 2,
"created_at": "2018-04-27 18:46:29",
"updated_at": "2018-04-27 18:46:29"
},
{
"id": 2,
"product_id": 1,
"category_id": 1,
"parent_id": null,
"title": "Princess",
"status": "Active",
"sort_order": 1,
"created_at": "2018-04-27 18:46:29",
"updated_at": "2018-04-27 18:46:29"
},
{
"id": 3,
"product_id": 1,
"category_id": 1,
"parent_id": null,
"title": "Oval",
"status": "Active",
"sort_order": 3,
"created_at": "2018-04-27 18:46:29",
"updated_at": "2018-04-27 18:46:29"
},
{
"id": 4,
"product_id": 1,
"category_id": 1,
"parent_id": null,
"title": "Kite",
"status": "Active",
"sort_order": 8,
"created_at": "2018-04-27 18:46:29",
"updated_at": "2018-04-27 18:46:29"
},
{
"id": 5,
"product_id": 1,
"category_id": 1,
"parent_id": null,
"title": "1-5",
"status": "Active",
"sort_order": 4,
"created_at": "2018-04-27 18:46:29",
"updated_at": "2018-04-27 18:46:29"
},
{
"id": 6,
"product_id": 1,
"category_id": 1,
"parent_id": null,
"title": "6-10",
"status": "Active",
"sort_order": 9,
"created_at": "2018-04-27 18:46:29",
"updated_at": "2018-04-27 18:46:29"
},
{
"id": 8,
"product_id": 1,
"category_id": 1,
"parent_id": null,
"title": "-2",
"status": "Active",
"sort_order": 10,
"created_at": "2018-04-27 18:46:29",
"updated_at": "2018-04-27 18:46:29"
},
{
"id": 9,
"product_id": 1,
"category_id": 1,
"parent_id": null,
"title": "+2 -4",
"status": "Active",
"sort_order": 7,
"created_at": "2018-04-27 18:46:29",
"updated_at": "2018-04-27 18:46:29"
},
{
"id": 10,
"product_id": 1,
"category_id": 1,
"parent_id": null,
"title": "+4 -6 1/2",
"status": "Active",
"sort_order": 6,
"created_at": "2018-04-27 18:46:29",
"updated_at": "2018-04-27 18:46:29"
}
]
},
post_attributes在我存储的这个表中还有另一个表attribute_id，product_id它属于attribute和product表。
我想过滤attributes仅在表格中可用的数据，并且仅适用于带有和的表格post_attributes中可用的“产品” 。我怎样才能做到这一点 ？post_attributesproduct_idattribute_id
解决方案
要约束预先加载关系，您可以将闭包传递给预先加载查询，并查询可以使用whereHas函数的关系，因此它看起来像这样：
Post::with(['product.categories.attributes' => function($query) {
// Eager load constraint
$query->whereHas('post_attribute', function ($query) {
$query->where('product_id', 1); // Filter by the joined data
});
}])->whereStatus("Active")->get();
希望这对您有所帮助。