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Firestore says I have inequality filter on multiple properties, when I don't

I am trying to do a "small hack" to avoid reading the User document everytime the page loads. So I save it locally, everytime the page loads I get the local version, get the updated_at property and then do something like WHERE last_updated > {{updated_at}}. For that, I want to use this:
firebase.firestore().collection('User')
.where(firebase.firestore.FieldPath.documentId(), '==', firebase.auth().currentUser.uid)
.where('updated_at', '>', updated_at)
.get()
As you can see, I have one equality (==) and one inequality (>). Why do I get the following error on the console:
FirebaseError: Cannot have inequality filters on multiple properties: updated_at
at new t (https://www.gstatic.com/firebasejs/6.0.2/firebase-firestore.js:1:47054)
at t.fromRpcStatus (https://www.gstatic.com/firebasejs/6.0.2/firebase-firestore.js:1:116660)
at t.fromWatchChange (https://www.gstatic.com/firebasejs/6.0.2/firebase-firestore.js:1:125914)
at t.onMessage (https://www.gstatic.com/firebasejs/6.0.2/firebase-firestore.js:1:242411)
at https://www.gstatic.com/firebasejs/6.0.2/firebase-firestore.js:1:241212
at https://www.gstatic.com/firebasejs/6.0.2/firebase-firestore.js:1:241997
at https://www.gstatic.com/firebasejs/6.0.2/firebase-firestore.js:1:144869
I am doing this to try to avoid reading from the database if the local version is the same as the one in the database. Maybe if you have a better way, please let me know.
Thanks

firebaser here
The equality check you have on documentId() is internally converted into a range check by Firestore, because the keys are stored as the last items in existing indexes (if I understand correctly). And that means that server-side you're trying to perform two inequality/range checks, which isn't allowed.
So the behavior you are seeing is correct. But it's definitely not intuitive, and the error message is also not helpful. We'll look for a way to improve the error message by detecting this combination.

I had the same problem and I implemented the following hack: I added the id as part of the field name on which I made the check for the latest version. If your logic allows you to do that, for you this would mean:
firebase.firestore().collection('User')
.where(id + '_updated_at', '>', updated_at)
.get()
This allows to bundle in just one where statement both the check on the id and on the date (documents with different ids wont have the field id + '_updated_at' and wont therefore be selected).
Worked like a charm for me

ArrayCollection (Collection of forms) index collision in Symfony 2

I am using Symfony2 to build up my page.
When I try to update a collection of forms (like described in the cookbook entry "How to Embed a Collection of Forms"), i get a collision of the indexes of the frontend and the indexes of the ArrayCollection in the backend.
I've got the relation User <-> Address (OneToMany). A user wants to create/update/delete his addresses, therefore he can add / delete in the frontend with the help of the javascript part new address elements. He does the following:
(1) Adds new address (has index: 0)
(2) Adds new address (has index: 1) and instantly removes this address again
(3) Adds new address (has index: 2).
When he clicks on save button, the following code saves/updates the user (and its addresses):
$this->em->persist($user);
$this->em->flush();
New addresses for example are then correctly persisted to the database.
Now the user wants to update the address e.g. with index 0.
When he now clicks on the save button, it updates the adress with "index 0", but at the same time, it adds again the address with "index 2" to the database (object).
To better understand the problem, i've drawn a small illustration (handmade, sorry for my bad art skills):
Now , i've got two times the address with "index 1" within my object / database.
I know why this happens, it's because the first "index 1" address gets mapped to the ArrayCollection element "number 1", and the second gets mapped to "number 2 "(because of the frontend name "index 2").
You can say: "it just fills up the addresses, until it reaches the frontend index in the backend"..
But how can I fix this behaviour ?
Site note:
This behaviour occurs using ajax requests, because if you would reload the page after clicking "save button", it would reindex the addresses in the frontend correctly with the indexes in the backend.
My suggestion to handle that situation:
Reindexing the frontend indexes after clicking save with the server side
indexes. Is this a clear / the only solution for my problem?

Yes, this is problem of Symfony form collection and it has no easy solution imho. But I have to ask why don't you do exactly the same thing what page refresh does? You can refresh only html snippet with collection. HTML code for snippet can come from server-side. Back to your question - yes, reindexing is good solution until you do not want to try write custom collection type on your own.
symfony/symfony/issues/7828
There is similar problem with validating in collection - symfony/symfony/issues/7468.
Well I think default collection type and the tutorial in Symfony docs has the some drawbacks. Hope that's help.

I have come round this issue on the client side by modifying the Javascript/Jquery code given in the Symfony Documentation.
Instead of numbering the new elements by counting the sub-elements, I am looking at the last element's id and extracting its index with a regular expression.
When adding an element, I am incrementing the last index by 1. That way, I never use the same index.
Here is my code :
// Initializing default index at 0
var index = 0;
// Looking for collection fields in the form
var $findinput = $container.find(':input');
// If fields found then looking for last existing index
if ( $findinput.length > 0 ) {
// Reading id of last field
var myString = $findinput.last().attr('id')
// Setting regular expression to extract number from id containing letters, hyphens and underscores
var myRegex = /^[-_A-Za-z]+([0-9]+)[-_A-Za-z]*$/
// Executing regular expression on last collection field id
var test = myRegex.exec(myString);
// Extracting last index and incrementing by 1
if (test.length > 0) index = parseInt(test[1]) + 1;
}

I ran into this problem a couple of times during the past two years. Usually, following the Symfony tutorial How to Embed a Collection of Forms does the job just fine. You need to do a little bit javascript coding to add the "edit/update" functionality, but other than that - you should be just fine using this approach.
If, on the other hand, you have a really complex form which uses AJAX to validate/save/calculation/business logic/etc, I've found it's usually a better to store the final data into an array in the session. After submitting the form, inside the if($form->isValid()){...} block, you would have
$collection = new ArrayCollection($mySessionPlainArray);
$user->setAddress($collection);
I would like to warn you to be careful with the serialization of your data - you might get some awkward exceptions or misbehavior if you're using entities (see my question).
I'm sorry I can't provide more code, but the solution to this problem sometimes is quite complex.

How to read from another row in javascript step of Pentaho?

I'm working on an ETL process with Pentaho Data Integration (Spoon, before Kettle).
In the Modified Javascript step of Pentaho you can set a start, end and transform script. In the transform script you can write code that it will be executed only for each row, and from here I don't know how to access to data of the previous row (if it's possible).
I need access to the previous row because all rows are ordered by product, store and date (respectively), and the goal is to get the quantity on hand from the previous row and add the quantity sell or received on the current row (this would be the same product, same store but different date). I also need accessing to the previous row to compare the product and store of the current row with the previous row, because if someone of them changes I must to restart the field quantity_on_hand (I do it with a field of all columns named initial_stock).
On pseudocode would be something like this (if I hadn't the restriction of that the code written on the step is executed only for each row):
while(all_rows_processed()){
current_row.quantity_on_hand = current_row.initial_stock;
while(id_product_current_row == id_product_previous_row && id_store_current_row == id_store_previous_row){
current_row.quantity_on_hand = previous_row.quantity_on_hand + current_row.stock_variation;
}
}
This question related couldn't help me.
Any ideas to solve my problem would be appreciated.

May I ask you to reconsider Group By step? It seems suitable for your scenario.
If you sort the stream accordingly to your combination date/store/article, you can calculate cumulative sum for sell/received quantity. This way you can have a running total of inventory variation that would be reset on a group basis.
Also give a look both at this blog post and at the forum post it quotes.

I doubt you need to go to JavaScript for this. Check out the Analytic query step. That will allow you to bring a value from the previous row into the current.
The JavaScript step gives you tremendous flexibility, but if you can do it with the regular transform steps, it will typically be much faster.

use Analytic Query. By Using this Step u can access the previous / next record. Actually, not only prev and next record that you can read, but you can read N Rows Fordward or N Rows Back Wards.
Check the following URL for clearer expalanation :
http://wiki.pentaho.com/display/EAI/Analytic+Query
http://www.nicholasgoodman.com/bt/blog/2009/01/30/the-death-of-prevrow-rowclone/

Thanks for all, I've got the solution to my problem.
I've combined all your suggestions and I've used the Analytic Query, Modified Javascript and Group by steps.
Although the question wasn't very well formulated, the problem I had was to calculate the stock level on each row (there was one row for each product, date and store combination).
First (obviously later than sort rows by product_id, store_id and date ascending), I used the Analytic Query step to group by product_id and store_id, because with this step I've got a new field previous_date to identify the first row of each group (previous_date=null on the row of the group where date was the oldest).
Then I needed to calculate the quantity_on_hand of each group [product,store] at first row (first date of each group because it's sorted by date) because the initial_stock is different for each group. This is because of (sum(quantity_received) - sum(quantity sold)) != quantity_on_hand.
Finally (and the key was here), I used the Group by step like #andtorg suggested and do it as the next image shows.
This link that #andtorg suggested was very useful. It includes even two .ktr example files.
Thank you so much for help!

pass multidimensional javascript array to another page

I have a multidimensional array that is something like this
[0]string
[1]-->[0]string,[1]string,[2]string
[2]string
[3]string
[4]-->[0]string,[1]string,[2]string[3]string,[4]string,[5]INFO
(I hope that makes sense)
where [1] and [4] are themselves arrays which I could access INFO like myArray[4][5].
The length of the nested arrays ([1] and [4]) can varry.
I use this method to store, calculate, and distribute data across a pretty complicated form.
Not all the data thats storred in the array makes it to an input field so its not all sent to the next page when the form's post method is called.
I would like to access the array the same way on the next page as I do on the first.
Thoughts:
Method 1:
I figure I could load all the data into hidden fields, post everything, then get those values on the second page and load themm all back into an array but that would require over a hundred hidden fields.
Method 2:
I suppose I could also use .join() to concatenate the whole array into one string, load that into one input, post it , and use .split(",") to break it back up. But If I do that im not sure how to handel the multidimensional asspect of it so that I still would be able to access INFO like myArray[4][5] on page 2.
I will be accessing the arrary with Javascript, the values that DO make it to inputs on page 1 will be accessed using php on page 2.
My question is is there a better way to acomplish what I need or how can I set up the Method 2 metioned above?
This solved my problem:
var str = JSON.stringify(fullInfoArray);
sessionStorage.fullInfoArray = str;
var newArr = JSON.parse(sessionStorage.fullInfoArray);
alert(newArr[0][2][1]);

If possible, you can use sessionStorage to store the string representation of your objects using JSON.stringify():
// store value
sessionStorage.setItem('myvalue', JSON.stringify(myObject));
// retrieve value
var myObject = JSON.parse(sessionStorage.getItem('myvalue'));
Note that sessionStorage has an upper limit to how much can be stored; I believe it's about 2.5MB, so you shouldn't hit it easily.

Keep the data in your PHP Session and whenever you submit forms update the data in session.
Every page you generate can be generated using this data.
OR
If uou are using a modern browser, make use of HTML5 localStorage.
OR
You can do continue with what you are doing :)

Related Parameters in HTML

I have a table of rows and columns on an HTML-based entry form that allows the user to edit multiple records. Each row corresponds to a database record and each column to a database field.
When the user submits the form, the server needs to figure out which request parameter belongs to which row. The method I've been using for years is to prefix or suffix each HTML input element's name to indicate the row it belongs to. For example, all input elements would have the suffix "row1" so that the server would know that request parameters whose names end with "row1" are field values for the first row.
While this works, one caveat of the suffix/prefix approach is that you're adding a constraint that you can't name any other elements with a particular suffix/prefix. So I wonder if there's a better, more elegant approach. I'm using JSP for the presentation layer, by the way.
Thanks.

I don't know JSP very well, but in PHP you would define your input fields' names with an array syntax.
<input name='person[]'>
<input name='person[]'>
<input name='person[]'>
When PHP receives a form like that, it gives you an array (within the standard $_POST array), thus:
$_POST['person']=array('alice','bob','charlie');
Which makes it very easy to deal with having as many sets of fields as you want.
You can also explicitly name the array elements:
<input name='person[teamleader]'>
<input name='person[developer1]'>
would give you an array with those keys. If your current prefixes are meaningful beyond simply numbering the records, this would solve that problem.
I don't know whether the identical syntax would work for JSP, but I imagine it would allow something very similar.
Hope that helps.

Current user agents send back the values in the order of the fields as presented to the user.
This means that you could (theoretically) drop the prefix/suffix altogether and sort it out based on the ordering of the values. You'd get something like
/?name=Tom&gender=M&name=Jane&gender=F&name=Roger&gender=M
I don't know how your framework returns that, but many return it as lists of each value
name = [Tom, Jane, Roger]
gender = [M, F, M]
If you pop an element off of each list, you should get a related set that you can work with.
The downside to this is that it relies on a standard behavior which is not actually required by the specification. Still... it's a convenient solution with a behavior that won't be problematic in practice.

When browsers POST that information back to the server, it is just a list of parameters:
?name_row1=Jeff&browser_row1=Chrome&name_row2=Mark&browser_row2=IE8
So really, I think you can answer a simpler question: how do you relate keys in a key-value list?
Alternatively, you can go to a more structured delivery method (JSON or XML), which will automatically give you a structured data format. Of course, this means you'll need to build this value on the browser first, then send it via AJAX (or via the value of a hidden input field) and then unpack/deserialize it in the server code.
XML:
<rows>
<row><id>1</id><name>Jeff</name><browser>Chrome</browser></row>
<row>...</row>
</rows>
or JSON:
[{ "name":"Jeff", "browser":"Chrome"}, { "name":"Mark", "browser":"IE8" }]
There are many resources/tutorials on how to do this... Google it. Or go with the ostensible StackOverflow consensus and try jQuery.