Firebase-admin不会写入数据库，不会出现错误

Firebase admin isn't writing to the database.

Firebase admin没有写入数据库。

I am instantiating the database:

我正在实例化数据库:

var db = admin.database();

Then setting up a reference to the table I want:

然后建立对我想要的表的引用:

var systemsRef = db.ref("systems/");

I then have a function to check if the 'system', (an encrypted hardware id), exists.

然后我有一个函数来检查“系统”(加密的硬件id)是否存在。

function isSystemRegistered(id){
  var isTrue;
  systemsRef.once('value', function(snapshot) {
      isTrue = (snapshot.hasChild(id))? true : false;
  });
  return isTrue;
}

Which, as of yet returns false; which is true, because it doesn't exist yet. If the system doesn't exist, it writes the data.

它返回false;这是对的，因为它还不存在。如果系统不存在，它将写入数据。

const sysID = getSysID();
var sys.info.name = generateUniqueSystemName();

if(isSystemRegistered(sysID){
  console.log("system is already registered!");
} else {
  msystemsRef.set({
      sysID : sys.info.name
    }, function(error){
        console.log('There was an error while attempting to write to database: ' + error);
      });
  });
}

I've experimented, and temporarily made my prototype database fully public for a few minutes, just to be sure my rules weren't the issue... They weren't: still no bueno. No writes to the database... and no errors.

我做了实验，暂时将我的原型数据库完全公开了几分钟，只是为了确保我的规则不是问题所在……他们不是:仍然不是布埃诺。不对数据库进行写入……并没有错误。

I tried a different set, just be sure:

我尝试了不同的设置，只是确定:

msystemsRef.set("I'm writing data", function(error) {
  if (error) {
    alert("Data could not be saved." + error);
  } else {
    alert("Data saved successfully.");
  }
});

Again, I'm using an admin account, with public rules, so I should see a now I'm writing data table, just below root. Nothing...

同样，我使用的是管理帐户和公共规则，所以我现在应该看到我正在写一个数据表，就在root下面。没有什么……

So I switched tactics and attempted to push to the database with the canned tutorial, with my database still fully public:

所以我改变了策略，尝试用罐装的教程推送到数据库中，而我的数据库仍然是完全公开的:

systemsRef.push({sysID : sys.info.name});

And nothing... Want am I missing?

和什么……我想失踪?

2 个解决方案

#1

Make sure the credentials and databaseURL are correct.

确保凭证和数据库都是正确的。

admin.initializeApp({
    credential: admin.credential.cert(serviceAccount),
    databaseURL: databaseURL
});

Check if they're matching - credential from one app and databaseURL from another existing app could produce such result.

检查它们是否匹配——来自一个应用程序的凭据和来自另一个现有应用程序的databaseURL可以生成这样的结果。

If you are not loading credential's data from file but from somewhere else, make sure it's not modified - I had an issue with newlines in private key when putting the credential's data to shell variable.

如果您没有从文件中加载凭据的数据，而是从其他地方加载，请确保它没有被修改——在将凭据的数据放入shell变量时，我在私钥中有一个问题。

#2

In isSystemRegistered you're returning the synchronized value of isTrue which is undefined.

在issystemregistration中，您将返回未定义的isTrue的同步值。

You should return the promise of the .once('value') method and in the calling method attach a then() to check if it exists.

您应该返回.once('value')方法的承诺，并在调用方法附加一个then()以检查它是否存在。

You can also use the snapshot.exists() to check on a reference for existence.

您还可以使用snapshot.exist()检查存在的引用。

Edit:

编辑:

Suggested edit:

建议修改:

var systemRef = admin.database('system');

function isSystemRegistered(id) {
  return systemRef.child(id).once('value')
    .then(function (snap) {
      return snap.exists();
    });
}

function writeData(aSystem) {
  var sysId = generateUniqueSystemName();
  return systemRef.child(sysId)
    .once('value')
    .then(function (snapshot) {
      if (!snapshot.exists()) {
        return systemRef.child(sysId).update(aSystem);
      }

      // Here `sysId === snapshot.key`
      return systemRef.child(sysId).set(aSystem);
    })
    .catch(function (err) {
       console.error(err);
    });
}

Running on Raspberry Pi raises some more questions.

在树莓派上奔跑会引出更多的问题。

How does it connect to the internet?
它如何连接到互联网?
How fast is the connection?
连接有多快?
What NodeJS version do you run?
你运行什么NodeJS版本?
Did this run successfully on your PC?
这个在你的电脑上运行成功吗?

#1