How I do get blogpostId firestore?

Question

My problem is getting the document id from firestore.

How I do fetch Users/documentid/Comments/documentid ?

Data class:

public class BlogPostId {


  @Exclude
  public String BlogPostId;

  public <T extends BlogPostId> T withId(@NonNull final String id) {
    this.BlogPostId = id;
    return (T) this;
  }
}

AddActivity:

private String blog_post_id;

Oncreate
blog_post_id = getIntent().getStringExtra("blog_post_id");

btn click
final String descff = icerikedit.getText().toString();

Map<String, Object> commentsMap = new HashMap<>();
            commentsMap.put("descff", descff);
            commentsMap.put("user_id", current_user_id);
            commentsMap.put("timestamp", FieldValue.serverTimestamp());

            firebaseFirestore.collection("Users/"+blog_post_id+"/Comments").add(commentsMap).addOnCompleteListener(new OnCompleteListener<DocumentReference>() {
    @Override
    public void onComplete(@NonNull Task<DocumentReference> task) {


        if(task.isSuccessful()){

            Toast.makeText(FFicerikAdd.this, "Başarılı efe!", Toast.LENGTH_SHORT).show();

            Intent sab=new Intent(getApplicationContext(),FFicerik.class);
            sab.putExtra("blog_post_id",blog_post_id);

            startActivity(sab);

        }

Answer 1

Unfortunately, there is no way in Cloud Firestore to get the name Mehmet which exists within the zSNQ...mUUF document and the name ahmet which exists within the SinifDevam document in a single query.

Queries in Firestore are shallow, they only get items from the collection that the query is run against. There is no way to get documents from another top-level collection and or from a subcollections in a single query. Firestore doesn't support queries across different collections in one step. A single query may only use properties of documents in only a single collection.

To solve this, you should add all user objects within a single collection and query it accordingly.