Flutter Firestore where clause using map

Question

When a new activity is posted i add a new post document into the collection. Inside this document i have a map where users add confirmation to the event marking it as true a

Answer 1

You'll want to turn the confirmations field into an array, and use the (relatively recent) array-contains and arrayUnion operations.

The equivalent query with an array like that would become:

var snap = await Firestore.instance
    .collection('user_posts')        
    .where("confirmations", arrayContains: user.id)
    .getDocuments();

And this way you only need an index on confirmations, which is added automatically.

For more on these see:

• the blog post introducing these operations
• the documentation on updating arrays
• the documentation on array membership queries