Question

我已经弄清楚了如何从Firebase中保存和检索日期，但是在将JSON保存到变量中时遇到了问题。我已经将变量设置为usersDB，但是当我console.log（）变量时，它以 undefined

注销

//firebase setup
var db = admin.database(); 
var ref = db.ref("server/saving-data/fireblog"); //var for databaseURL


//firebase
var usersRef = ref.child("users"); //where I am pulling the data from
var usersDB // init var

ref.on("value", function(snapshot) {
     console.log(snapshot.val()); // logs the way I want it
     usersDB = snapshot.val(); // trying to save json
}, function (errorObject) {
    console.log("The read failed:" + errorObject.code);
})

console.log(usersDB) // logs undefined

app.get("", function(req, res) {
    res.render("index", {users : usersDB});
})

app.post("/", function(req, res) {
    console.log(req.body.user.username);
    usersRef.child(req.body.user.username).set({
        name:  req.body.user.name,
        email: req.body.user.email,
    });
    res.redirect('/');
});

Answer 1

尝试将变量传递到另一个函数中并将其保存在其中：

ref.on("value", function(snapshot) {
     console.log(snapshot.val()); // logs the way I want it
     func_(snapshot.val()); // trying to save json
}, function (errorObject) {
    console.log("The read failed:" + errorObject.code);
})

function func_(json){
   console.log(json) // logs undefined
}

如何将Firebase JSON数据保存到Node.JS中的变量中

1 个答案: