I have problems using the filter scoring feature of Algolia, it isnt sorting my results according the criteria provided.
I have this structure on my documents of Firebase:
{ ...data, skills: { expert:['someId','someId'], proficient: ['someId','someId'], novice: ['someId'] } }
And now I want to filter and sort my results in order if the id searched is in expert, it will be shown at top of the list, then the documents with that id in proficient.. and that way.
According to the Algolia docs, with filter scoring in this way should result:
const { hits, nbHits } = await index.search<T>(text, { filters : '( skills.expert:"someId"<score=3> OR skills.proficient:"someId"<score=2> OR skills.novice:"someId"<score=1> )', page: page, });
but my results are not being sorted.
Related
I'm struggling to formulate a supabase db query from multiple tables, whilst using a value from a URL.
I have 3 tables (simplified)...
series > id, series
authors > id, name
books > id, title, series_id(fk), authors_id(fk)
I want to get a list of books in a series, along with the author and series name from the following URL...
app.com/series. i.e. app.com/harrypotter
I can get the series name using getServerSideProps, but struggling how to write my query to supabase. Every way I write it either gives me a NULL object or a 500 error.
I feel like I should be querying the books table and then be able to get the series and author names through the foreign keys. But the query that it's centred around is the series name, which is in the series table. So unsure of the db query to do it, or whether I should structure my db table's in a different way?
export async function getServerSideProps( context ) {
const { series } = context.query;
...
return {
props: {
...
}
};
}
Thanks for any help in advance!
Please ensure you have foreign keys set up, and then you can use Supabase to query foreign table examples (SQL join).
There needs to be more data to give an exact answer, but here are the relevant docs.
Supabase get a single record
Supabase select - not super obvious, but you need to click the button Query foreign tables
Supabase filters
I also included logs and a try/catch so you can see your exact errors and where your code is failing.
const Page = (props) => {
console.log(props)// logged to browser's console
return <>Your page<>;
}
export async function getServerSideProps( context ) {
try {
const { series } = context.query;
console.log("series", series); // ensure series is present and check if is an object
const { data, error } = await supabase.from('series')
.select(`
id,
title,
book (
title // you can also use `*` check out select all docs
author (
name
)
)
`)
.eq('id', series)
.limit(1)
console.log("error", error);
console.log("data", data);
return {
props: {
series: data
}
}
} catch (e) {
console.log(e);
}
}
export default Page;
Note: getServerSideProps logs will show up in your server's console (where you run npm dev) - not the browser's console. You should remove the console logs once you figure out what's happening.
I use firebase database filter orderBy seller_id in nested list, why is the result null? thank you 🙏
:rules Firebase
var url = Uri.parse(
'https://MeDatabase.firebasedatabase.app/orders.json?auth=$authToken&orderBy="list_produk/seller_id"&equalTo="$idUser"');
try {
final response = await http.get(url);
if (response.statusCode >= 400) {
throw EasyLoading.showError('Cek Koneksi Internetmu!');
}
final extractData =
convert.jsonDecode(response.body) as Map<String, dynamic>;
print('inii orderan');
print(extractData);
if (extractData == null) {
return _orders = [];
}
} catch (e) {
throw e;
}
You're trying to index and order each order on its list_produk/seller_id property.
But if I look at your JSON data, there is no list_produk/seller_id property under the order. There's only list_produk/1/seller_id, and presumably list_produk/0/seller_id. Those are not the same as what you use in your rules/query, so the query returns no results.
Firebase Realtime Database queries function on a single, flat list of nodes. The value you order/filter on must exist at a fixed path under each direct child node.
So in your example, you can search across all orders on for example id_user, or you can search across the seller_id of the products in a specific order, but you can't search across all sellers of products in all orders.
In other words: your current data structure makes it easy to find the products and sellers per order, it does however not make it each to find the orders per product across all users. To allow that you'll want to add an additional data structure, typically known as a reverse index, that maps from each seller_id to the orders that contain products from that seller.
For more on this, I recommend checking out:
Firebase query if child of child contains a value
Firebase Query Double Nested
Many to Many relationship in Firebase
You can get the child count via
firebase_node.once('value', function(snapshot) { alert('Count: ' + snapshot.numChildren()); });
But I believe this fetches the entire sub-tree of that node from the server. For huge lists, that seems RAM and latency intensive. Is there a way of getting the count (and/or a list of child names) without fetching the whole thing?
The code snippet you gave does indeed load the entire set of data and then counts it client-side, which can be very slow for large amounts of data.
Firebase doesn't currently have a way to count children without loading data, but we do plan to add it.
For now, one solution would be to maintain a counter of the number of children and update it every time you add a new child. You could use a transaction to count items, like in this code tracking upvodes:
var upvotesRef = new Firebase('https://docs-examples.firebaseio.com/android/saving-data/fireblog/posts/-JRHTHaIs-jNPLXOQivY/upvotes');
upvotesRef.transaction(function (current_value) {
return (current_value || 0) + 1;
});
For more info, see https://www.firebase.com/docs/transactions.html
UPDATE:
Firebase recently released Cloud Functions. With Cloud Functions, you don't need to create your own Server. You can simply write JavaScript functions and upload it to Firebase. Firebase will be responsible for triggering functions whenever an event occurs.
If you want to count upvotes for example, you should create a structure similar to this one:
{
"posts" : {
"-JRHTHaIs-jNPLXOQivY" : {
"upvotes_count":5,
"upvotes" : {
"userX" : true,
"userY" : true,
"userZ" : true,
...
}
}
}
}
And then write a javascript function to increase the upvotes_count when there is a new write to the upvotes node.
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);
exports.countlikes = functions.database.ref('/posts/$postid/upvotes').onWrite(event => {
return event.data.ref.parent.child('upvotes_count').set(event.data.numChildren());
});
You can read the Documentation to know how to Get Started with Cloud Functions.
Also, another example of counting posts is here:
https://github.com/firebase/functions-samples/blob/master/child-count/functions/index.js
Update January 2018
The firebase docs have changed so instead of event we now have change and context.
The given example throws an error complaining that event.data is undefined. This pattern seems to work better:
exports.countPrescriptions = functions.database.ref(`/prescriptions`).onWrite((change, context) => {
const data = change.after.val();
const count = Object.keys(data).length;
return change.after.ref.child('_count').set(count);
});
```
This is a little late in the game as several others have already answered nicely, but I'll share how I might implement it.
This hinges on the fact that the Firebase REST API offers a shallow=true parameter.
Assume you have a post object and each one can have a number of comments:
{
"posts": {
"$postKey": {
"comments": {
...
}
}
}
}
You obviously don't want to fetch all of the comments, just the number of comments.
Assuming you have the key for a post, you can send a GET request to
https://yourapp.firebaseio.com/posts/[the post key]/comments?shallow=true.
This will return an object of key-value pairs, where each key is the key of a comment and its value is true:
{
"comment1key": true,
"comment2key": true,
...,
"comment9999key": true
}
The size of this response is much smaller than requesting the equivalent data, and now you can calculate the number of keys in the response to find your value (e.g. commentCount = Object.keys(result).length).
This may not completely solve your problem, as you are still calculating the number of keys returned, and you can't necessarily subscribe to the value as it changes, but it does greatly reduce the size of the returned data without requiring any changes to your schema.
Save the count as you go - and use validation to enforce it. I hacked this together - for keeping a count of unique votes and counts which keeps coming up!. But this time I have tested my suggestion! (notwithstanding cut/paste errors!).
The 'trick' here is to use the node priority to as the vote count...
The data is:
vote/$issueBeingVotedOn/user/$uniqueIdOfVoter = thisVotesCount, priority=thisVotesCount
vote/$issueBeingVotedOn/count = 'user/'+$idOfLastVoter, priority=CountofLastVote
,"vote": {
".read" : true
,".write" : true
,"$issue" : {
"user" : {
"$user" : {
".validate" : "!data.exists() &&
newData.val()==data.parent().parent().child('count').getPriority()+1 &&
newData.val()==newData.GetPriority()"
user can only vote once && count must be one higher than current count && data value must be same as priority.
}
}
,"count" : {
".validate" : "data.parent().child(newData.val()).val()==newData.getPriority() &&
newData.getPriority()==data.getPriority()+1 "
}
count (last voter really) - vote must exist and its count equal newcount, && newcount (priority) can only go up by one.
}
}
Test script to add 10 votes by different users (for this example, id's faked, should user auth.uid in production). Count down by (i--) 10 to see validation fail.
<script src='https://cdn.firebase.com/v0/firebase.js'></script>
<script>
window.fb = new Firebase('https:...vote/iss1/');
window.fb.child('count').once('value', function (dss) {
votes = dss.getPriority();
for (var i=1;i<10;i++) vote(dss,i+votes);
} );
function vote(dss,count)
{
var user='user/zz' + count; // replace with auth.id or whatever
window.fb.child(user).setWithPriority(count,count);
window.fb.child('count').setWithPriority(user,count);
}
</script>
The 'risk' here is that a vote is cast, but the count not updated (haking or script failure). This is why the votes have a unique 'priority' - the script should really start by ensuring that there is no vote with priority higher than the current count, if there is it should complete that transaction before doing its own - get your clients to clean up for you :)
The count needs to be initialised with a priority before you start - forge doesn't let you do this, so a stub script is needed (before the validation is active!).
write a cloud function to and update the node count.
// below function to get the given node count.
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);
exports.userscount = functions.database.ref('/users/')
.onWrite(event => {
console.log('users number : ', event.data.numChildren());
return event.data.ref.parent.child('count/users').set(event.data.numChildren());
});
Refer :https://firebase.google.com/docs/functions/database-events
root--|
|-users ( this node contains all users list)
|
|-count
|-userscount :
(this node added dynamically by cloud function with the user count)
I am currently using ReactiveAggregate to find a subset of Product data, like this:
ReactiveAggregate(this, Products, [
{ $match: {}},
{ $project: {
title: true,
image: true,
variants: {
$filter: {
input: "$variants",
as: "variant",
cond: {
$setIsSubset: [['$$variant.id'], user.variantFollowing]
}
}
}
}}
], { clientCollection: 'aggregateVariants' }
As you can see, a variant is returned if user.variantFollowing matches. When a user 'follows' a product, the ID is added to their object. However, if I understand correctly, this is not triggering ReactiveAggregate to get the new subset when this happens. Only on a full page refresh do I get the correct (latest) data.
Is this the correct way to approach this?
I could store the user's ID as part of the Product object, but the way this would be stored would be nested two places, and I think I would need the Mongo 3.5 updates to then be able to accurately update this. So i'm looking for how to do this in Meteor 1.5+ / Mongo 3.2.12
So, I've been able to get there by adding autorun to the subscription of the aggregate collection, like this:
Template.followedProducts.onCreated(function() {
Meteor.subscribe('products');
this.autorun(() => {
Meteor.subscribe('productsFollowed');
});
... rest of function
For context, productsFollowed is the subscription to retrieve aggregateVariants from the original question.
Thanks to robfallows in this post: https://forums.meteor.com/t/when-and-how-to-use-this-autorun/26075/6
You can get the child count via
firebase_node.once('value', function(snapshot) { alert('Count: ' + snapshot.numChildren()); });
But I believe this fetches the entire sub-tree of that node from the server. For huge lists, that seems RAM and latency intensive. Is there a way of getting the count (and/or a list of child names) without fetching the whole thing?
The code snippet you gave does indeed load the entire set of data and then counts it client-side, which can be very slow for large amounts of data.
Firebase doesn't currently have a way to count children without loading data, but we do plan to add it.
For now, one solution would be to maintain a counter of the number of children and update it every time you add a new child. You could use a transaction to count items, like in this code tracking upvodes:
var upvotesRef = new Firebase('https://docs-examples.firebaseio.com/android/saving-data/fireblog/posts/-JRHTHaIs-jNPLXOQivY/upvotes');
upvotesRef.transaction(function (current_value) {
return (current_value || 0) + 1;
});
For more info, see https://www.firebase.com/docs/transactions.html
UPDATE:
Firebase recently released Cloud Functions. With Cloud Functions, you don't need to create your own Server. You can simply write JavaScript functions and upload it to Firebase. Firebase will be responsible for triggering functions whenever an event occurs.
If you want to count upvotes for example, you should create a structure similar to this one:
{
"posts" : {
"-JRHTHaIs-jNPLXOQivY" : {
"upvotes_count":5,
"upvotes" : {
"userX" : true,
"userY" : true,
"userZ" : true,
...
}
}
}
}
And then write a javascript function to increase the upvotes_count when there is a new write to the upvotes node.
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);
exports.countlikes = functions.database.ref('/posts/$postid/upvotes').onWrite(event => {
return event.data.ref.parent.child('upvotes_count').set(event.data.numChildren());
});
You can read the Documentation to know how to Get Started with Cloud Functions.
Also, another example of counting posts is here:
https://github.com/firebase/functions-samples/blob/master/child-count/functions/index.js
Update January 2018
The firebase docs have changed so instead of event we now have change and context.
The given example throws an error complaining that event.data is undefined. This pattern seems to work better:
exports.countPrescriptions = functions.database.ref(`/prescriptions`).onWrite((change, context) => {
const data = change.after.val();
const count = Object.keys(data).length;
return change.after.ref.child('_count').set(count);
});
```
This is a little late in the game as several others have already answered nicely, but I'll share how I might implement it.
This hinges on the fact that the Firebase REST API offers a shallow=true parameter.
Assume you have a post object and each one can have a number of comments:
{
"posts": {
"$postKey": {
"comments": {
...
}
}
}
}
You obviously don't want to fetch all of the comments, just the number of comments.
Assuming you have the key for a post, you can send a GET request to
https://yourapp.firebaseio.com/posts/[the post key]/comments?shallow=true.
This will return an object of key-value pairs, where each key is the key of a comment and its value is true:
{
"comment1key": true,
"comment2key": true,
...,
"comment9999key": true
}
The size of this response is much smaller than requesting the equivalent data, and now you can calculate the number of keys in the response to find your value (e.g. commentCount = Object.keys(result).length).
This may not completely solve your problem, as you are still calculating the number of keys returned, and you can't necessarily subscribe to the value as it changes, but it does greatly reduce the size of the returned data without requiring any changes to your schema.
Save the count as you go - and use validation to enforce it. I hacked this together - for keeping a count of unique votes and counts which keeps coming up!. But this time I have tested my suggestion! (notwithstanding cut/paste errors!).
The 'trick' here is to use the node priority to as the vote count...
The data is:
vote/$issueBeingVotedOn/user/$uniqueIdOfVoter = thisVotesCount, priority=thisVotesCount
vote/$issueBeingVotedOn/count = 'user/'+$idOfLastVoter, priority=CountofLastVote
,"vote": {
".read" : true
,".write" : true
,"$issue" : {
"user" : {
"$user" : {
".validate" : "!data.exists() &&
newData.val()==data.parent().parent().child('count').getPriority()+1 &&
newData.val()==newData.GetPriority()"
user can only vote once && count must be one higher than current count && data value must be same as priority.
}
}
,"count" : {
".validate" : "data.parent().child(newData.val()).val()==newData.getPriority() &&
newData.getPriority()==data.getPriority()+1 "
}
count (last voter really) - vote must exist and its count equal newcount, && newcount (priority) can only go up by one.
}
}
Test script to add 10 votes by different users (for this example, id's faked, should user auth.uid in production). Count down by (i--) 10 to see validation fail.
<script src='https://cdn.firebase.com/v0/firebase.js'></script>
<script>
window.fb = new Firebase('https:...vote/iss1/');
window.fb.child('count').once('value', function (dss) {
votes = dss.getPriority();
for (var i=1;i<10;i++) vote(dss,i+votes);
} );
function vote(dss,count)
{
var user='user/zz' + count; // replace with auth.id or whatever
window.fb.child(user).setWithPriority(count,count);
window.fb.child('count').setWithPriority(user,count);
}
</script>
The 'risk' here is that a vote is cast, but the count not updated (haking or script failure). This is why the votes have a unique 'priority' - the script should really start by ensuring that there is no vote with priority higher than the current count, if there is it should complete that transaction before doing its own - get your clients to clean up for you :)
The count needs to be initialised with a priority before you start - forge doesn't let you do this, so a stub script is needed (before the validation is active!).
write a cloud function to and update the node count.
// below function to get the given node count.
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);
exports.userscount = functions.database.ref('/users/')
.onWrite(event => {
console.log('users number : ', event.data.numChildren());
return event.data.ref.parent.child('count/users').set(event.data.numChildren());
});
Refer :https://firebase.google.com/docs/functions/database-events
root--|
|-users ( this node contains all users list)
|
|-count
|-userscount :
(this node added dynamically by cloud function with the user count)