CODEWITHSUNDEEP
reactjsfirebasefirebase-realtime-databasereact-redux
Youngsun Paik
Youngsun Paik

Reputation: 65

Writing to Firebase DB using redux action writes whole new data in the DB

I am trying to write to Firebase DB in a React application. It adds new data entry if I use DB reference and set method. However, it writes a whole new data when I use the same method through redux action.

This is the code that works.

      const notesRef = firebase.database().ref('notes');
      const noteRef = notesRef.child(this.state.noteId);

      const note = {
        text: this.state.text,
        timestamp: this.state.timestamp,
        title: this.titleTextArea.value,
      }

      noteRef.set(note);

This is the action

      export const addNote = (newNoteId, newNote) => async dispatch => {
            notesRef.child(newNoteId).set(newNote);
      };

      const note = {
        text: this.state.text,
        timestamp: this.state.timestamp,
        title: this.titleTextArea.value,
      }

      this.props.addNote(this.state.noteId, note);

Bad result:

notes: "a6ff48e4-f34a-483f-a639-b0dbfd703009"

Good result:

notes:
      b85def67-3877-4d2f-b5c7-23d8295768ad
            text: "{\"ops\":[{\"insert\":\"fsasfs\\n\"}]}"
            timestamp: 1557467143056
            title: "asfa"

      e4290153-a40c-464f-a92a-39eded74bd2a
            text: "{\"ops\":[{\"insert\":\"sadfasdfsd\\n\"}]}"
            timestamp: 1557467154054
            title: "asdfsdaf"

Upvotes: 0

Views: 103

Answers (2)

Stephen Phillips
Stephen Phillips

Reputation: 681

Basic rule is Set overrides and Update is specific to each node. Use update instead. You can also use push to have firebase automatically generate a unique node name:

Set:

Using set() overwrites data at the specified location, including any child nodes.

Update:

To simultaneously write to specific children of a node without overwriting other child nodes, use the update() method.

https://firebase.google.com/docs/database/web/read-and-write https://firebase.google.com/docs/database/admin/save-data

Upvotes: 1

Codesingh
Codesingh

Reputation: 3384

So what 'set' function of firebase does it replace existing data with the new one. Use 'update' function to update db.

//get new key
var newPostKey = firebase.database().ref().child(newNoteId).push().key;

//Update existing
 export const addNote = (newNoteId, newNote) => async dispatch => {
    let update = {}
    update[newPostKey] = newNote
    notesRef.update(update);
 };

Happy Coding :)

Upvotes: 1

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