Why I cant query sub-collection or a document from a sub-collection in Firebase?

问题

I have this query where I am trying to get a document from a sub-collection but it doesnt get anything, neither it shows any error:

const db = firebase.firestore(9;
let ref = db.collection('myCollection').doc('EzGNfNl63LQvjdauFWosG08Ishj2').collection('privat').doc('privat');
        ref.get()
            .then(doc => {  //it doesnt continue to next line, just executes this one
                if (doc.exists) {
                    console.log("Doc exists:", doc.data())
                }else{
                    console.log("Doc deostn exists:")
                }

            }).catch(error => {
                console.log('Error getting restaurant data: ', error);
            })

However, if I try to query only a document from the collection then it works:

let ref = db().collection('myCollection').doc('EzGNfNl63LQvjdauFWosG08Ishj2');

EDIT: Screenshot added

回答1:

Change this:

const db = firebase.firestore.
let ref = db().collection('myCollection').doc('EzGNfNl63LQvjdauFWosG08Ishj2').collection('privat').doc('privat');
        ref.get()
            .then(doc => {  //it doesnt continue to next line, just executes this one
                if (doc.exists) {
                    console.log("Doc exists:", doc.data())
                }else{
                    console.log("Doc deostn exists:")
                }

            }).catch(error => {
                console.log('Error getting restaurant data: ', error);
            })

Into this:

const db = firebase.firestore();
let ref = db.collection('myCollection').doc('EzGNfNl63LQvjdauFWosG08Ishj2').collection('privat').doc('privat');
        ref.get()
            .then(doc => {  //it doesnt continue to next line, just executes this one
                if (doc.exists) {
                    console.log("Doc exists:", doc.data())
                }else{
                    console.log("Doc deostn exists:")
                }

            }).catch(error => {
                console.log('Error getting restaurant data: ', error);
            })

firestore() is a method and db is a constant.

来源：https://stackoverflow.com/questions/61147374/why-i-cant-query-sub-collection-or-a-document-from-a-sub-collection-in-firebase