在云函数中进行多个Firestore查询

Question

我想创建一个计划的云功能，该功能在每个月底产生员工奖金。为此，我需要列出所有员工，该用户的所有发票以及所有现有奖金的清单，所有清单都包含在Firestore集合中。因此，我需要3个Firestore集合，但找不到如何在云函数中查询的解决方案。

我暂时尝试过：

exports.generateBonus = functions.https.onRequest(async (req, res) => {
  var listEmployee = [];
  var listInvoice = [];
  const employeeRef = admin.firestore().collection('employee');
  const invoiceRef = admin.firestore().collection('invoice');
  const promiseFacture = new Promise((resolve,reject)=>{
      return factureRef.get();
  })
  .then(list_invoice => {
    listInvoice = list_invoice.docs.map(doc => {
      return doc.data();
    });
  })
  .catch(error => {
    console.log("got an error",error);        
  });
  const promiseEmployee = new Promise((resolve,reject)=>{
    return employeeRef.get();
  })
  .then(list_employee => {
    listEmployee = list_user.docs.map(doc => {
      return doc.data();
    });
  })
  .catch(error => {
    console.log("got an error",error);        
  });
  Promise.all([promiseInvoice, promiseEmployee])
  .then((values) => {
    console.log(values);
    return res.send('ok');
  })
  .catch(error => {
    console.log(error);
  })
});

但是它在1秒内返回了我两个空数组

有人知道该怎么做吗？谢谢

Answer 1

以下内容，使用destructuring assignment syntax，可以完成：

exports.generateBonus = functions.https.onRequest(async (req, res) => {

    const employeesRef = admin.firestore().collection('employee');
    const invoicesRef = admin.firestore().collection('invoice');

    const [employeesSnapshot, invoicesSnapshot] = await Promise.all([employeesRef.get(), invoicesRef.get()]);

    const listEmployees = employeesSnapshot.docs;
    const listInvoices = invoicesSnapshot.docs;

    //Logging
    listEmployees.forEach(snap => {
       console.log(snap.data());
    });
    listInvoices.forEach(snap => {
       console.log(snap.data());
    });

    //...
    res.status(200).send(...);   //Adapt the ... to a meaningful value
});

---

请注意，get()方法返回一个Promise，因此您无需将其包装在另一个Promise中。

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（（请注意，我已将s添加到所有collections / snapshots变量名称中。）>]