Argthtjtr

I need to query Firestore, but it keeps telling me I need an index. Problem is that isn't realistic, since EVERY user would require a custom index based on their UserId. For security, I can't allow anyone access unless canAccess.${userID} == true as in the example below. But if I were to take ALL items, and filter them by date client-side I would be fetching hundreds of thousands of items every time I change the date range, so it isn't practical.

this.db.collection('items')

       .where(`canAccess.${userId}`, '==', true)

       .where('date', '>=', startDate)

       .where('date', '<=', endDate);

How would one going about fetching only the items they are allowed to access, and only between the chosen date range?

You'll have to restructure your documents in order to perform this query. Consider putting the uids that can access the document in a field with a List type called canAccess. Then query the list with array-contains after you create an index on that field.

this.db.collection('items')

       .where('canAccess', 'array-contains', userId)

       .where('date', '>=', startDate)

       .where('date', '<=', endDate);