[英]fetch 3 schema value using mongoose node JS
我有 3 個集合架構 CategorySchema、SubCategorySchema、ProductSchema,如下所示。
var CategorySchema = new mongoose.Schema({
catgory_name: {
type: String,
required: [true, "Catgory name is required"]
},
modified_date: {
type: Date
}
});
module.exports = mongoose.model("Category", CategorySchema);
var SubCategorySchema = new Schema({
subcatgory_name: {
type: String,
required: [true, "subcategory name is required"]
},
category_id: {
type: Schema.Types.ObjectId,
ref: "Category",
required: [true, "category id is required"]
},
modified_date: {
type: Date
},
is_active: {
type: Boolean,
default: 1
}
});
module.exports = mongoose.model("SubCategories", SubCategorySchema);
const ProductSchema = new Schema({
product_name: {
type: String,
required: [true, "Product name is required"]
},
product_image: {
type: String,
required: [true, "Product image is required"]
},
category_id: {
type: Schema.Types.ObjectId,
ref: "Category",
required: [true, "category is required"]
},
subcategory_id: {
type: Schema.Types.ObjectId,
ref: "Subcategory",
required: [true, "Subcategory is required"]
},
modified_date: {
type: Date
},
is_active: {
type: Boolean,
default: 1
}
});
module.exports = mongoose.model("Products", ProductSchema);
在這里,我想獲取所有活動產品(is_active = 1)以及相應的類別和活動子類別(is_active = 1)。 無需檢查類別的 is_active 條件,但需要檢查子類別和產品的活動條件
我在節點 JS 控制器中嘗試了以下代碼
router.get("/list", (req, res, next) => {
products
.find({ is_active: true })
.populate("category_id")
.populate("subcategory_id", null, SubCategory, {
match: { is_active: true }
})
//.where("subcategory_id", !null)
.then(products => res.json({ status: 200, data: products }))
.catch(err => res.json(err));
});
但即使子類別處於非活動狀態,它也會返回產品數據
您可以使用 mongodb 聚合框架仍然使用 mongoose 進行查詢。
router.get("/list", (req, res, next) => {
products
.aggregate([
{
$match: {
is_active: true
}
},
{
$lookup: {
from: "subcategories",
localField: "subcategory_id",
foreignField: "_id",
as: "subcategories"
}
},
{
$unwind: "$subcategories"
},
{
$match: {
"subcategories.is_active": true
}
},
{
$lookup: {
from: "categories",
localField: "category_id",
foreignField: "_id",
as: "category"
}
},
{
$addFields: {
category: {
$arrayElemAt: ["$category", 0]
}
}
}
])
.then(products => res.json({ status: 200, data: products }))
.catch(err => res.status(500).json(err));
});
讓我們有這些示例文檔:
db={
"products": [
{
"modified_date": "2020-01-08T09:06:51.544Z",
"is_active": true,
"_id": "5e159ca1bd95457404b22bc3",
"product_name": "Product1 Name",
"product_image": "Product1 Image",
"category_id": "5e159b77a746036404b5f0ae",
"subcategory_id": "5e159befbd95457404b22bc2"
},
{
"modified_date": "2020-01-08T09:06:51.544Z",
"is_active": false,
"_id": "5e159cb8bd95457404b22bc4",
"product_name": "Product2 Name",
"product_image": "Product2 Image",
"category_id": "5e159b77a746036404b5f0ae",
"subcategory_id": "5e159befbd95457404b22bc2"
},
{
"modified_date": "2020-01-08T09:06:51.544Z",
"is_active": true,
"_id": "5e159d3abd95457404b22bc6",
"product_name": "Product3 Name",
"product_image": "Product3 Image",
"category_id": "5e159b77a746036404b5f0ae",
"subcategory_id": "5e159ce0bd95457404b22bc5"
}
],
"categories": [
{
"modified_date": "2020-01-08T09:04:18.003Z",
"_id": "5e159b77a746036404b5f0ae",
"catgory_name": "Main Category 1"
}
],
"subcategories": [
{
"modified_date": "2020-01-08T09:06:51.544Z",
"is_active": true,
"_id": "5e159befbd95457404b22bc2",
"subcatgory_name": "Sub Category 1",
"category_id": "5e159b77a746036404b5f0ae"
},
{
"modified_date": "2020-01-08T09:06:51.544Z",
"is_active": false,
"_id": "5e159ce0bd95457404b22bc5",
"subcatgory_name": "Sub Category 2",
"category_id": "5e159b77a746036404b5f0ae"
}
]
}
結果將是:
[
{
"_id": "5e159ca1bd95457404b22bc3",
"category": {
"_id": "5e159b77a746036404b5f0ae",
"catgory_name": "Main Category 1",
"modified_date": "2020-01-08T09:04:18.003Z"
},
"category_id": "5e159b77a746036404b5f0ae",
"is_active": true,
"modified_date": "2020-01-08T09:06:51.544Z",
"product_image": "Product1 Image",
"product_name": "Product1 Name",
"subcategories": {
"_id": "5e159befbd95457404b22bc2",
"category_id": "5e159b77a746036404b5f0ae",
"is_active": true,
"modified_date": "2020-01-08T09:06:51.544Z",
"subcatgory_name": "Sub Category 1"
},
"subcategory_id": "5e159befbd95457404b22bc2"
}
]
如您所見,即使產品 3 處於活動狀態,也未檢索到,因為其子類別5e159ce0bd95457404b22bc5
未處於活動狀態。
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