如何在 firestore 中获取单个文档并将其显示在网站上

Question

I cant't find a way to get a single document from Cloud Firestore on a website. Let's say I have this Collection on my Cloud Firestore (Not realtime DB):

StoreSales:
 StoreA
    Jan:1
    Feb:5
    Mar:10
    Apr:2
    May:3 
 StoreB 
    Jan:1
    Feb:5
    Mar:5
    Apr:6
    May:3
 StoreC
    Jan:1
    Feb:5
    Mar:2
    Apr:2
    May:1

And I have this code to retrieve some data:

const Stores = document.querySelector('#sales-list');

function renderSales(doc){
    let li = document.createElement('li');
    let sales = document.createElement('span');

    li.setAttribute('data-id', doc.id);
    sales.textContent = doc.data().StoreSales;

    li.appendChild(sales);

    Stores.appendChild(li);
}

db.collection('StoreSales').get().then(snapshot => {
    snapshot.docs.forEach(doc => {
            console.log(doc.id, ' => ', doc.data());
        renderSales(doc);
    });
});

And what that ends up doing is getting all data, no matter the document and no matter what's inside the sub collections, it will get for example what's on Store A, B and C, and their contents.

I wanted to target and display specific data, like for example show the StoreB April sales. What can I modify to get this result?

Answer 1

Getting a single document when you know its ID is a straightforward case covered in the documentation . I suggest reviewing it. You can use doc() to create a reference to that document.

db.collection('StoreSales').doc('StoreA').get().then(snapshot => {
    // Do what you want with the DocumentSnapshot here
});