远程方法，查询和循环关系数据

Question

我有一个模型，Bill，hasMany Orders.

如果我在 Bill 中编写了一个远程方法，我如何查询一个账单并遍历它的订单？

bill.json

{
  "name": "bill",
  ...
  "relations": {
    "orders": {
      "type": "hasMany",
      "model": "order",
      "foreignKey": "orderId"
    }
}

bill.js

Bill.doLoop = async function(id, body, callback) {
  let bill = await Bill.findById(id, {include: ['orders']})

  for (let order of bill.orders) {
    console.log(order);
  }
}

如果我这样做，我会收到以下错误：

Unhandled error for request POST /api/bills/1/doLoop : TypeError: bill.orders[Symbol.iterator] is not a function

如果我将 bill 转换为 JSON 字符串并返回，则可以访问订单，但这感觉非常脏：

let billJson = JSON.parse(JSON.stringify(bill))

for (let order of billJson.orders) {
  console.log(order);
}

Answer 1

我在 Include filter - Access included objects 的 Loopbacks 文档中找到了答案：

In the Node.js API, call toJSON() to convert the returned model instance with related items into a plain JSON object.

更新代码使其有效：

Bill.doLoop = async function(id, body, callback) {
  let bill = await Bill.findById(id, {include: ['orders']})

  for (let order of bill.toJSON().orders) {
    console.log(order);
  }
}

远程方法，查询和循环关系数据

Remote method, query and loop over relation data

node.js

loopbackjs