如何在数据模型中添加子集合？扑

Question

如何获取子集合中的列表产品并将其添加到我创建的数据模型中。 我正在尝试从供应商处将所有产品添加到购物车中。 这是我的数据库的结构

这是我想要做的数据代码

class cartModel {
      vendorCartModel? vendorCart;
      List<productCartModel>? productsInCart;
    
      cartModel();
    
      cartModel.fromSnapshot(DocumentSnapshot snap){
        vendorCart = vendorCartModel.fromSnapShot(snap);
        productsInCart = ?????? (here is the part where i don't know what to do')
      }
      }
================

class vendorCartModel {
  bool selected = false;
  String? storeName;
  String? uid;
  String? userId;
  String? vendorToken;
  GeoPoint? storeLocation;

  vendorCartModel();
  vendorCartModel.fromSnapShot(DocumentSnapshot snap){
    storeName = snap["storeName"];
    uid = snap["uid"];
    userId = snap["userId"];
    vendorToken = snap["vendorToken"];
    storeLocation = snap["storeLocation"];
  }
}
==========================

class productCartModel {
  bool selected = false;
  String? name;
  List<dynamic>? imgUrl;
  String? uid;
  String? vendorUid;
  int? quantity;
  double? sellingPrice;
  double? sellerPrice;
  double? oldPrice;
  double? weight;
  bool? shipping;
  int? minOrder;
  
  productCartModel();

  productCartModel.fromSnapshot(DocumentSnapshot snap){
    uid = snap["uid"];
    vendorUid = snap["vendorUid"];
    imgUrl = snap["imgUrl"];
    name = snap["name"];
    weight = snap["weight"];
    sellingPrice = double.parse(snap["sellingPrice"].toString());
    sellerPrice = double.parse(snap["sellerPrice"].toString());
    oldPrice = double.parse(snap["oldPrice"].toString());
    quantity = snap["quantity"];
    minOrder = snap["minOrder"];
    shipping = snap["shipping"];
  }
}

================ 这是我的数据库结构

• 购物车（收藏）
  • 字段（这将用作供应商）
    • 产品（子系列）

=============== 这是我的查询

await _fStoreIns
            .collection('cart')
            .doc(vendorId).get().then((value){
cartModel = cartModel.fromSnapshot(value);
})

提前致谢。

Answer 1

首先，我们获取供应商的数据，然后是 productsData，并将两者都传递给cartModel.fromSnapShot 方法。

使用这个查询：

DocumentSnapshot<Map<String, dynamic>> vendorData =
    await _fStoreIns.collection('cart').doc(vendorId).get();
QuerySnapshot<Map<String, dynamic>> productsData = await _fStoreIns
    .collection('cart')
    .doc(vendorId)
    .collection('products')
    .get();
cartModel = cartModel.fromSnapshot(vendorData, productsData);

如下定义您的cartModel.fromSnapshot：

cartModel.fromSnapshot(DocumentSnapshot vendorData, QuerySnapshot productsData) {
  vendorCart = vendorCartModel.fromSnapShot(vendorData);
  productsInCart = productsData.docs
      .map((e) => productCartModel.fromSnapShot(e)).toList();
}

Answer 2

用于更新数据

final pushData = FirebaseFirestore.instance.collection('cart');
pushData
        .doc(cardId)
        .collection("products")
        .doc(productId)
        .set({
         changes:"Changes"
         })

用于添加数据

final pushData = FirebaseFirestore.instance.collection('cart');
pushData
        .doc(cardId)
        .collection("products")
        .add({
          data: "DATA"
        });

用于获取数据

await pushData
        .doc(productid)
        .collection("products")
        .orderBy("timeStamp", descending: true) // if you want to order by time or whatever
        .limit(50) //for adding limit add limit
        .get();

Answer 3

如果我理解正确，您在 fbCloudStore 中具有以下结构

-vendors (collection)
 -vendor (doc)
  -products (colecction)
   -product (doc)

要获取您可以执行的特定子集合：

final vendorId = 'Replace with vendor Id';
    final _querySnapshot = await _fStoreIns
            .collection('vendors')
            .doc(vendorId)
            .collection('products')
            .get();
    
    
    for(final doc in _querySnapshot.docs){
      //do stuff here
      ProductModel.fromJson(doc.data());
    }

Answer 4

我的结构是这样的

- cart (collection)
  - fields (this will be used as vendor)
    - products ( sub collection )

我想要的是这样的东西

await _fStoreIns
            .collection('cart')
            .doc(vendorId).get().then((value){
cartModel = cartModel.fromSnapshot(value);
})

我的 cartModel.fromSnapshot 在哪里

cartModel.fromSnapshot(DocumentSnapshot snap){
    vendorCart = vendorCartModel.fromSnapShot(snap);
    productCart.add(ChkOutItemModel.fromSnapshot(snap));
  }