如何更新 firebase 列表中的字段？

Question

I have this collection in Firebase

I have tried to modify the value within the map notes of a specific subject, I could not do it and I have tried in several ways without success I would really appreciate a little help.

I get the data in that way, but I can not update that data.

this.firestore.collection('school').doc('254')
            .get().toPromise().then(doc => {
            if (doc.exists) {
                const student = doc.data().class.find(value => {
                    return value.name === 'john';
                });
                console.log('student', student);
                /*
                Here edit student.notes.math = newValue
                 */
            }
        });

PD: I'm currently work with Angular 7.

Answer 1

I don't see that your code attempts to update the document that you found. Changing the data in memory doesn't change the contents of the document. You will have to write additional code to update the document with your changes to the class field.

See:

• Firestore: How to update specific field of document?
• The documentation

this.firestore
    .collection('school')
    .doc('254')
    .update("class", NEW_FIELD_CONTENTS)

You will need to provide the entire contents of the updated class field. Firestore doesn't have any operations that let you update an array item at a specific index.