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  • Hack a Linksys Router into a Ambient Data Monitor

    - by Jason Fitzpatrick
    If you have a data source (like a weather report, bus schedule, or other changing data set) you can pull it and display it with an ambient data monitor; this fun build combines a hacked Linksys router and a modified toy bus to display transit arrival times. John Graham-Cumming wanted to keep an eye on the current bus arrival time tables without constantly visiting the web site to check them. His workaround turns a hacked Linksys router, a display, a modified London city bus (you could hack apart a more project-specific enclosure, of course), and a simple bit code that polls the bus schedule’s API, into a cool ambient data monitor that displays the arrival time, in minutes, of the next two buses that will pass by his stop. The whole thing could easily be adapted to another API to display anything from stock prices to weather temps. Hit up the link below for more information on the project. Ambient Bus Arrival Monitor Hacked from Linksys Router [via Make] Make Your Own Windows 8 Start Button with Zero Memory Usage Reader Request: How To Repair Blurry Photos HTG Explains: What Can You Find in an Email Header?

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  • Flashback Data Archives: Ein gutes Gedächtnis für DBA und Entwickler

    - by Heinz-Wilhelm Fabry (DBA Community)
    Daten werden gespeichert und zum Teil lange aufbewahrt. Mitunter werden Daten nach ihrer ersten Speicherung geändert, vielleicht sogar mehrfach. Je nach gesetzlicher oder betrieblicher Vorgabe müssen die Veränderungen sogar nachverfolgbar sein. Damit sind zugleich Mechanismen gefordert, die sicherstellen, dass die Folge der Versionen lückenlos ist. Und implizit bedeutet das zusätzlich, dass die Versionen auch vor Löschen und Verändern geschützt sein müssen. Das Versionieren kann über die Anwendung, mit der die Daten auch erfasst werden, erfolgen, über Trigger oder über besondere Werkzeuge. Jede dieser Lösungen hat ihre eigenen Schwächen. Zusätzlich steht die Frage nach dem Schutz vor unerlaubtem Löschen oder Ändern versionierter Daten im Raum. Flashback Data Archives lösen diese Frage, denn sie bieten nicht nur einen wirksamen Mechanismus zum Versionieren von Datensätzen, sondern sie schützen diese Versionen auch vor Veränderung und löschen sie schließlich sogar automatisch nach Ablauf ihrer Aufbewahrungsfrist.Ursprünglich wurden die Archive als eigenständige Option zur Enterprise Edition der Oracle Database 11g unter dem Namen Total Recall eingeführt. Ende Juni 2012 verloren die Flashback Data Archives ihren Status als eigenständige Option. Weil die Archive aber grundsätzlich komprimiert wurden, hat Oracle sie stattdessen zu einem Feature der Advanced Compression Option der Enterprise Edition (ACO) gemacht. Seit der Version 11.2.0.4 der Datenbank ist das Komprimieren aber für die Archive nicht mehr zwangsläufig, sondern optional. Damit gibt es lizenzrechtlich erneut eine Änderung: Wer die Kompression verwendet, der muss nach wie vor ACO lizensieren. Wer die Flashback Data Archives dagegen ohne Kompression verwendet - also zum Beispiel Entwickler -, dem stehen sie ab 11.2.0.4 aufwärts im Lieferumfang aller Editionen der Datenbank zur Verfügung. Diese Änderung ist in den Handbüchern zur Lizensierung der Versionen 11.2 und 12.1 der Datenbank dokumentiert. Im Rahmen der DBA Community ist bereits über die Flashback Data Archives berichtet worden. Der hier vorliegende Artikel ersetzt alle vorangegangenen Beiträge zum Thema.

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  • Data indexing frameworks fit for large E-Commerce applications

    - by Dabu
    we wrote and still maintain a large E-Commerce application. Our feature list resembles what you would expect from most shops. We'd like to improve some of our features, and now the search/suggestion list functionality (enter some letters, a JScripted suggestion list appears) has caught our eye. Currently, we use http://xapian.org/. It has some drawbacks. Firstly, it's not actually the right solution. It has been created to index documents, not ever-changing data in a granularity that an E-Commerce application would need. Secondly, the load on the database is significant when we reindex all data every night. We'd like a framework that has been designed for indexing database data, which can add to the index easily and without much load, which can supply data changes in the backoffice quickly to the frontend without much load and delay. I'm aware of the fact that Xapian is Open Source and even Free Software, so we could adapt it to our needs if we decided to invest the time and manpower. But taking a quick look around for a solution more suited seems fair, right? Oh, and commercial applications are fine, too. FOSS is not required. Thanks a bunch.

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  • Compressing 2D level data

    - by Lucius
    So, I'm developing a 2D, tile based game and a map maker thingy - all in Java. The problem is that recently I've been having some memory issues when about 4 maps are loaded. Each one of these maps are composed of 128x128 tiles and have 4 layers (for details and stuff). I already spent a good amount of time searching for solutions and the best thing I found was run-length enconding (RLE). It seems easy enough to use with static data, but is there a way to use it with data that is constantly changing, without a big drop in performance? In my maps, supposing I'm compressing the columns, I would have 128 rows, each with some amount of data (hopefully less than it would be without RLE). Whenever I change a tile, that whole row would have to be checked and I'm affraid that would slow down too much the production (and I'm in a somewhat tight schedule). Well, worst case scenario I work on each map individually, and save them using RLE, but it would be really nice if I could avoind that. EDIT: What I'm currently using to store the data for the tiles is a 2D array of HashMaps that use the layer as key and store the id of the tile in that position - like this: private HashMap< Integer, Integer [][]

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  • Non use of persisted data – Part deux

    - by Dave Ballantyne
    In my last blog I showed how persisted data may not be used if you have used the base data on an include on an index. That wasn't the only problem ive had that showed the same symptom.  Using the same code as before,  I was executing similar to the below : select BillToAddressID,SOD.SalesOrderDetailID,SOH.CleanedGuid from sales.salesorderheader SOH join Sales.SalesOrderDetail SOD on SOH.SalesOrderID = SOD.SalesOrderID But,  due to a distribution error in statistics i found it necessary to use a table hint.  In this case, I wanted to force a loop join select BillToAddressID,SOD.SalesOrderDetailID,SOH.CleanedGuid from sales.salesorderheader SOH inner loop join Sales.SalesOrderDetail SOD on SOH.SalesOrderID = SOD.SalesOrderID   But, being the diligent  TSQL developer that I am ,looking at the execution plan I noticed that the ‘compute scalar’ operator was again calling the function.  Again,  profiler is a more graphic way to view this…..   All very odd,  just because ive forced a join , that has NOTHING, to do with my persisted data then something is causing the data to be re-evaluated. Not sure if there is any easy fix you can do to the TSQL here, but again its a lesson learned (or rather reinforced) examine the execution plan of every query you write to ensure that it is operating as you thought it would.

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  • What conventions or frameworks exist for MVVM in Perl?

    - by Will Sheppard
    We're using Catalyst to render lots of webforms in what will become a large application. I don't like the way all the form data is confusingly into a big hash in the Controller, before being passed to the template. It seems jumbled up and messy for the template. I'm sure there are real disadvantages that I haven't described properly... Are there? One solution is to just decide on a convention for the hash, e.g.: { defaults => { type => ['a', 'b', 'c'] }, input => { type => 'a' }, output => { message => "2 widgets found of type a", widgets => [ 'foo', 'bar' ] } } Another way is to store the page/form data as attributes in a class (a ViewModel?), and pass a whole object to the template, which it could use like this: <p class="message">[% model.message %]<p> [% FOREACH widget IN model.widgets %] Which way is more flexible for large applications? Are there any other solutions or existing Catalyst-compatible frameworks?

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  • Displaying a Grid of Data in ASP.NET MVC

    One of the most common tasks we face as a web developers is displaying data in a grid. In its simplest incarnation, a grid merely displays information about a set of records - the orders placed by a particular customer, perhaps; however, most grids offer features like sorting, paging, and filtering to present the data in a more useful and readable manner. In ASP.NET WebForms the GridView control offers a quick and easy way to display a set of records in a grid, and offers features like sorting, paging, editing, and deleting with just a little extra work. On page load, the GridView automatically renders as an HTML <table> element, freeing you from having to write any markup and letting you focus instead on retrieving and binding the data to display to the GridView. In an ASP.NET MVC application, however, developers are on the hook for generating the markup rendered by each view. This task can be a bit daunting for developers new to ASP.NET MVC, especially those who have a background in WebForms. This is the first in a series of articles that explore how to display grids in an ASP.NET MVC application. This installment starts with a walk through of creating the ASP.NET MVC application and data access code used throughout this series. Next, it shows how to display a set of records in a simple grid. Future installments examine how to create richer grids that include sorting, paging, filtering, and client-side enhancements. We'll also look at pre-built grid solutions, like the Grid component in the MvcContrib project and JavaScript-based grids like jqGrid. But first things first - let's create an ASP.NET MVC application and see how to display database records in a web page. Read on to learn more! Read More >

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  • Generate a Word document from list data

    - by PeterBrunone
    This came up on a discussion list lately, so I threw together some code to meet the need.  In short, a colleague needed to take the results of an InfoPath form survey and give them to the user in Word format.  The form data was already in a list item, so it was a simple matter of using the SharePoint API to get the list item, formatting the data appropriately, and using response headers to make the client machine treat the response as MS Word content.  The following rudimentary code can be run in an ASPX (or an assembly) in the 12 hive.  When you link to the page, send the list name and item ID in the querystring and use them to grab the appropriate data. // Clear the current response headers and set them up to look like a word doc.HttpContext.Current.Response.Clear();HttpContext.Current.Response.Charset ="";HttpContext.Current.Response.ContentType ="application/msword";string strFileName = "ThatWordFileYouWanted"+ ".doc";HttpContext.Current.Response.AddHeader("Content-Disposition", "inline;filename=" + strFileName);// Using the current site, get the List by name and then the Item by ID (from the URL).string myListName = HttpContext.Current.Request.Querystring["listName"];int myID = Convert.ToInt32(HttpContext.Current.Request.Querystring["itemID"]);SPSite oSite = SPContext.Current.Site;SPWeb oWeb = oSite.OpenWeb();SPList oList = oWeb.Lists["MyListName"];SPListItem oListItem = oList.Items.GetItemById(myID);// Build a string with the data -- format it with HTML if you like. StringBuilder strHTMLContent = newStringBuilder();// *// Here's where you pull individual fields out of the list item.// *// Once everything is ready, spit it out to the client machine.HttpContext.Current.Response.Write(strHTMLContent);HttpContext.Current.Response.End();HttpContext.Current.Response.Flush();

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  • PASS Summit Preconference and Sessions

    - by Davide Mauri
    I’m very pleased to announce that I’ll be delivering a Pre-Conference at PASS Summit 2012. I’ll speak about Business Intelligence again (as I did in 2010) but this time I’ll focus only on Data Warehouse, since it’s big topic even alone. I’ll discuss not only what is a Data Warehouse, how it can be modeled and built, but also how it’s development can be approached using and Agile approach, bringing the experience I gathered in this field. Building the Agile Data Warehouse with SQL Server 2012 http://www.sqlpass.org/summit/2012/Sessions/SessionDetails.aspx?sid=2821 I’m sure you’ll like it, especially if you’re starting to create a BI Solution and you’re wondering what is a Data Warehouse, if it is still useful nowadays that everyone talks about Self-Service BI and In-Memory databases, and what’s the correct path to follow in order to have a successful project up and running. Beside this Preconference, I’ll also deliver a regular session, this time related to database administration, monitoring and tuning: DMVs: Power in Your Hands http://www.sqlpass.org/summit/2012/Sessions/SessionDetails.aspx?sid=3204 Here we’ll dive into the most useful DMVs, so that you’ll see how that can help in everyday management in order to discover, understand and optimze you SQL Server installation, from the server itself to the single query. See you there!!!!!

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  • ASP.NET MVVM Handling multiple Data Transfer Objects on a single page

    - by meffect
    I have an asp.net mvc "edit" page which allows the user to make edits to the parent entity, and then also "create" child entities on the same page. Note: I'm making these data transfer objects up. public class CustomerViewModel { public int Id { get; set; } public Byte[] Timestamp { get; set; } public string CustomerName { get; set; } public etc.. public CustomerOrderCreateViewModel CustomerOrderCreateViewModel { get; set; } } In my view I have two html form's. One for Customer "edit" Http Posts, and the other for CustomerOrder "create" Http Posts. In the view page, I load the CustomerOrder "create" form in using: <div id="CustomerOrderCreate"> @Html.Partial("Vendor/_CustomerOrderCreatePartial", Model.CustomerOrderCreateViewModel) </div> The CustomerOrder html form action posts to a different controller HttpPost ActionResult than the Customer "edit" Action Result. My concern is this, on the CustomerOrder controller, in the HttpPost ActionResult [HttpPost] public ActionResult Create(CustomerOrderCreateViewModel vm) { if (!ModelState.IsValid) { return [What Do I Return Here] } ...[Persist to database code]... } I don't know what to return if the model state isn't valid. Right now it's not a problem, because jquery unobtrusive validation handles validation on the client. But what if I need more complex validation (ie: the server needs to handle the validation).

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  • PASS Summit Preconference and Sessions

    - by Davide Mauri
    I’m very pleased to announce that I’ll be delivering a Pre-Conference at PASS Summit 2012. I’ll speak about Business Intelligence again (as I did in 2010) but this time I’ll focus only on Data Warehouse, since it’s big topic even alone. I’ll discuss not only what is a Data Warehouse, how it can be modeled and built, but also how it’s development can be approached using and Agile approach, bringing the experience I gathered in this field. Building the Agile Data Warehouse with SQL Server 2012 http://www.sqlpass.org/summit/2012/Sessions/SessionDetails.aspx?sid=2821 I’m sure you’ll like it, especially if you’re starting to create a BI Solution and you’re wondering what is a Data Warehouse, if it is still useful nowadays that everyone talks about Self-Service BI and In-Memory databases, and what’s the correct path to follow in order to have a successful project up and running. Beside this Preconference, I’ll also deliver a regular session, this time related to database administration, monitoring and tuning: DMVs: Power in Your Hands http://www.sqlpass.org/summit/2012/Sessions/SessionDetails.aspx?sid=3204 Here we’ll dive into the most useful DMVs, so that you’ll see how that can help in everyday management in order to discover, understand and optimze you SQL Server installation, from the server itself to the single query. See you there!!!!!

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  • django-admin: creating,saving and relating a m2m model

    - by pastylegs
    I have two models: class Production(models.Model): gallery = models.ManyToManyField(Gallery) class Gallery(models.Model): name = models.CharField() I have the m2m relationship in my productions admin, but I want that functionality that when I create a new Production, a default gallery is created and the relationship is registered between the two. So far I can create the default gallery by overwriting the productions save: def save(self, force_insert=False, force_update=False): if not ( Gallery.objects.filter(name__exact="foo").exists() ): g = Gallery(name="foo") g.save() self.gallery.add(g) This creates and saves the model instance (if it doesn't already exist), but I don't know how to register the relationship between the two?

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  • Generate POCO classes in different project to the project with Entity Framework model

    - by Max
    I'm trying to use the Repository Pattern with EF4 using VS2010. To this end I am using POCO code generation by right clicking on the entity model designer and clicking Add code generation item. I then select the POCO template and get my classes. What I would like to be able to do is have my solution structured into separate projects for Entity (POCO) classes and another project for the entity model and repository code. This means that my MVC project could use the POCO classes for strongly typed views etc and not have to know about the repository or have to have a reference to it. To plug it all together I will have another separate project with interfaces and use IoC. Sounds good in my head I just don't know how to generate the classes into their own project! I can copy them and then change the namespaces on them but I wanted to avoid manual work whenever I change the schema in the db and want to update my model. Thanks

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  • Using NHibernate with an EAV data model

    - by devonlazarus
    I'm trying to leverage NH to map to a data model that is a loose interpretation of the EAV/CR data model. I have most of it working but am struggling with mapping the Entity.Attributes collection. Here are the tables in question: -------------------- | Entities | -------------------- | EntityId PK |-| | EntityType | | -------------------- | ------------- | V -------------------- | EntityAttributes | ------------------ --------------------------- -------------------- | Attributes | | StringAttributes | | EntityId PK,FK | ------------------ --------------------------- | AttributeId FK | -> | AttributeId PK | -> | StringAttributeId PK,FK | | AttributeValue | | AttributeType | | AttributeName | -------------------- ------------------ --------------------------- The AttributeValue column is implemented as an sql_variant column and I've implemented an NHibernate.UserTypes.IUserType for it. I can create an EntityAttribute entity and persist it directly so that part of the hierarchy is working. I'm just not sure how to map the EntityAttributes collection to the Entity entity. Note the EntityAttributes table could (and does) contain multiple rows for a given EntityId/AttributeId combination: EntityId AttributeId AttributeValue -------- ----------- -------------- 1 1 Blue 1 1 Green StringAttributes row looks like this for this example: StringAttributeId AttributeName ----------------- -------------- 1 FavoriteColor How can I effectively map this data model to my Entity domain such that Entity.Attributes("FavoriteColors") returns a collection of favorite colors? Typed as System.String?

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  • ASP.NET MVC 2 RC2 Model Binding with NVARCHAR NOT NULL column

    - by Gary McGill
    I have a database column defined as NVARCHAR(1000) NOT NULL DEFAULT(N'') - in other words, a non-nullable text column with a default value of blank. I have a model class generated by the Linq-to-SQL Classes designer, which correctly identifies the property as not nullable. I have a TextAreaFor in my view for that property. I'm using UpdateModel in my controller to fetch the value from the form and populate the model object. If I view the web page and leave the text area blank, UpdateModel insists on setting the property to NULL instead of empty string. (Even if I set the value to blank in code prior to calling UpdateModel, it still overwrites that with NULL). Which, of course, causes the subsequent database update to fail. I could check all such properties for NULL after calling UpdateModel, but that seems ridiculous - surely there must be a better way? Please don't tell me I need a custom model binder for such a simple scenario...!

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  • How to customize a many-to-many inline model in django admin

    - by Jonathan
    I'm using the admin interface to view invoices and products. To make things easy, I've set the products as inline to invoices, so I will see the related products in the invoice's form. As you can see I'm using a many-to-many relationship. In models.py: class Product(models.Model): name = models.TextField() price = models.DecimalField(max_digits=10,decimal_places=2) class Invoice(models.Model): company = models.ForeignKey(Company) customer = models.ForeignKey(Customer) products = models.ManyToManyField(Product) In admin.py: class ProductInline(admin.StackedInline): model = Invoice.products.through class InvoiceAdmin(admin.ModelAdmin): inlines = [FilteredApartmentInline,] admin.site.register(Product, ProductAdmin) The problem is that django presents the products as a table of drop down menus (one per associated product). Each drop down contains all the products listed. So if I have 5000 products and 300 are associated with a certain invoice, django actually loads 300x5000 product names. Also the table is not aesthetic. How can I change it so that it'll just display the product's name in the inline table? Which form should I override, and how?

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  • Default value for field in Django model

    - by Daniel Garcia
    Suppose I have a model: class SomeModel(models.Model): id = models.AutoField(primary_key=True) a = models.IntegerField(max_length=10) b = models.CharField(max_length=7) Currently I am using the default admin to create/edit objects of this type. How do I set the field 'a' to have the same number as id? (default=???) Other question Suppose I have a model: event_date = models.DateTimeField( null=True) year = models.IntegerField( null=True) month = models.CharField(max_length=50, null=True) day = models.IntegerField( null=True) How can i set the year, month and day fields by default to be the same as event_date field?

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  • Upload Image with Django Model Form

    - by jmitchel3
    I'm having difficulty uploading the following model with model form. I can upload fine in the admin but that's not all that useful for a project that limits admin access. #Models.py class Profile(models.Model): name = models.CharField(max_length=128) user = models.ForeignKey(User) profile_pic = models.ImageField(upload_to='img/profile/%Y/%m/') #views.py def create_profile(request): try: profile = Profile.objects.get(user=request.user) except: pass form = CreateProfileForm(request.POST or None, instance=profile) if form.is_valid(): new = form.save(commit=False) new.user = request.user new.save() return render_to_response('profile.html', locals(), context_instance=RequestContext(request)) #Profile.html <form enctype="multipart/form-data" method="post">{% csrf_token %} <tr><td>{{ form.as_p }}</td></tr> <tr><td><button type="submit" class="btn">Submit</button></td></tr> </form> Note: All the other data in the form saves perfectly well, the photo does not upload at all. Thank you for your help!

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  • How to prevent a javascript/backbone.js cloned model from sharing attributes

    - by user540727
    I'm working with backbone.js models, so I don't know if my question is particular to the way backbone handles cloning or if it applies to javascript in general. Basically, I need to clone a model which has an attribute property assigned an object. The problem is that when I update the parent or clone's attribute, the other model is also updated. Here is a quick example: var A = Backbone.Model.extend({}); var a = new A({'test': {'some': 'crap'}}); var b = a.clone(); a.get('test')['some'] = 'thing'; // I could also use a.set() to set the attribute with the same result console.log(JSON.stringify(a)) console.log(JSON.stringify(b)) which logs the following: {"test":{"some":"thing"}} {"test":{"some":"thing"}} I would prefer to clone a such that b won't be referencing any of its attributes. Any help would be appreciated.

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  • Django queries: Count number of objects with FK to model instance

    - by Chris Lawlor
    This should be easy but for some reason I'm having trouble finding it. I have the following: App(models.Model): ... Release(models.Model): date = models.DateTimeField() App = models.ForeignKey(App) ... How can I query for all App objects that have at least one Release? I started typing: App.objects.all().annotate(release_count=Count('??????')).filter(release_count__gt=0) Which won't work because Count doesn't span relationships, at least as far as I can tell. BONUS: Ultimately, I'd also like to be able to sort Apps by latest release date. I'm thinking of caching the latest release date in the app to make this a little easier (and cheaper), and updating it in the Release model's save method, unless of course there is a better way. Edit: I'm using Django 1.1 - not averse to migrating to dev in anticipation of 1.2 if there is a compelling reason though.

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  • Django unable to update model

    - by user292652
    i have the following function to override the default save function in a model match def save(self, *args, **kwargs): if self.Match_Status == "F": Team.objects.filter(pk=self.Team_one.id).update(Played=F('Played')+1) Team.objects.filter(pk=self.Team_two.id).update(Played=F('Played')+1) if self.Winner !="": Team.objects.filter(pk=self.Winner.id).update(Win=F('Win')+1, Points=F('Points')+3) else: return if self.Match_Status == "D": Team.objects.filter(pk=self.Team_one.id).update(Played=F('Played')+1, Draw = F('Draw')+1, Points=F('Points')+1) Team.objects.filter(pk=self.Team_two.id).update(Played=F('Played')+1, Draw = F('Draw')+1, Points=F('Points')+1) super(Match, self).save(*args, **kwargs) I am able to save the match model just fine but Team model does not seem to be updating at all and no error is being thrown. am i missing some thing here ?

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  • Calling a method from within a django model save() override

    - by Jonathan
    I'm overriding a django model save() method. Within the override I'm calling another method of the same class and instance which calculates one of the instance's fields based on other fields of the same instance. class MyClass(models.Model): field1 = models.FloatField() field2 = models.FloatField() field3 = models.FloatField() def calculateField1(self) self.field1 = self.field2 + self.field3 def save(self, *args, **kwargs): self.calculateField1() super(MyClass, self).save(*args, **kwargs) The override method is called when I change the model in admin. Alas I've discovered that within calculateField1() field2 and field3 have the values of the instance from before I edited them in admin. If I enter the instance again in admin and save again, only then field1 receives the correct value as field2 and field3 are already updated. Is this the correct behavior on django's side? If yes, then how can I use the new values within calculateField1? I cannot implement the calculation within the save() as calculateField1() actually quite long and I need it to be called from elsewhere.

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  • Django comparing model instances for equality

    - by orokusaki
    I understand that, with a singleton situation, you can perform such an operation as: spam == eggs and if spam and eggs are instances of the same class with all the same attribute values, it will return True. In a Django model, this is natural because two separate instances of a model won't ever be the same unless they have the same .pk value. The problem with this is that if a reference to an instance has attributes that have been updated by middleware somewhere along the way and it hasn't been saved, and you're trying to it to another variable holding a reference to an instance of the same model, it will return False of course because they have different values for some of the attributes. Obviously I don't need something like a singleton , but I'm wondering if there some official Djangonic (ha, a new word) method for checking this, or if I should simply check that the .pk value is the same with: spam.pk == eggs.pk I'm sorry if this was a huge waste of time, but it just seems like there might be a method for doing this, and something I'm missing that I'll regret down the road if I don't find it.

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  • Django model manager didn't work with related object when I do aggregated query

    - by Satoru.Logic
    Hi, all. I'm having trouble doing an aggregation query on a many-to-many related field. Let's begin with my models: class SortedTagManager(models.Manager): use_for_related_fields = True def get_query_set(self): orig_query_set = super(SortedTagManager, self).get_query_set() # FIXME `used` is wrongly counted return orig_query_set.distinct().annotate( used=models.Count('users')).order_by('-used') class Tag(models.Model): content = models.CharField(max_length=32, unique=True) creator = models.ForeignKey(User, related_name='tags_i_created') users = models.ManyToManyField(User, through='TaggedNote', related_name='tags_i_used') objects_sorted_by_used = SortedTagManager() class TaggedNote(models.Model): """Association table of both (Tag , Note) and (Tag, User)""" note = models.ForeignKey(Note) # Note is what's tagged in my app tag = models.ForeignKey(Tag) tagged_by = models.ForeignKey(User) class Meta: unique_together = (('note', 'tag'),) However, the value of the aggregated field used is only correct when the model is queried directly: for t in Tag.objects.all(): print t.used # this works correctly for t in user.tags_i_used.all(): print t.used #prints n^2 when it should give n Would you please tell me what's wrong with it? Thanks in advance.

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  • mvc2 validation problem (ambiguous reference between model and models)

    - by ile
    I followed instructions for mvc validation but I can't manage to solve this problem.... This is linq to sql model: I set Entity namespace to be CMS.Model If I try to declare partial class Article in Portal.Models namespace: public partial class Article { .... } Then, after using Article article somewhere in code I get following error: 'Article' is an ambiguous reference between 'Portal.Models.Article' and 'CMS.Model.Article' Portal is project name and CMS is area.... I followed these instructions I aslo created NerdDinner from scratch and in that example validation works. I can't figure out what am I doing wrong... someone noticed my mistake? Is it related with giving name to Entity namespace (in tutorial they used default one) Thanks in advance! PS I'd like to note that I'm c# newbie so I'm not really familiar with these partial classes

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