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• WPF/SL EventAggregator implementation with durable subscribers behavior?

  - by sha1dy

  Hi. Currently I'm building an application using latest Prism for Silverlight 4. I've a module and in that module I've two views with view models. Also I've a module view with two regions for each view. In module initialization I'm registering my views and view models in Unity container and also register views with corresponding regions. The problem is that views should display something similar to table-detail information - first view shows available entities ans the second view shows detail of selected entity. I need a way how to pass them initial selected entity. Newly created first view doesn't have any selected entity and newly created second view doesn't show any details. Currently I'm doing that this way: In module I create two view models and register them as instances in Unity container and then I register views as types for corresponding regions. Each view subscribes to EntitySelectedEvent from EventAggregator. Module initializer publish this event after initialization and this way two views are selecting the same entity. I know this looks ugly - I tried publishing this event from one of view models but the problems is that EventAggregator in Prism doesn't support durable subscribers - this means that if the second view model didn't subscribe to event before the first view model fired it, it won't receive and event. I know this is a normal behavior of EventAggregator, but I'm looking for a solution when view models can fire events without depending on initialization order of them - that is the first model can fire event before the second model was created and the second model will receive this 'queued' event after subscribing to it. Are there any other messaging implementations for WPF/SL which do support such behavior or using a mediator (in my example it's a module itself) isn't such a bad idea after all? One big problem with mediator is that models must be created right away in initialize and they can't be registered as types in container because this leads again to missing subscribers.

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• nhibernate many to many deletes

  - by asi farran

  I have 2 classes that have a many to many relationship. What i'd like to happen is that whenever i delete one side ONLY the association records will be deleted with no concern which side i delete. simplified model: classes: class Qualification { IList<ProfessionalListing> ProfessionalListings } class ProfessionalListing { IList<Qualification> Qualifications void AddQualification(Qualification qualification) { Qualifications.Add(qualification); qualification.ProfessionalListings.Add(this); } } fluent automapping with overrides: void Override(AutoMapping<Qualification> mapping) { mapping.HasManyToMany(x => x.ProfessionalListings).Inverse(); } void Override(AutoMapping<ProfessionalListing> mapping) { mapping.HasManyToMany(x => x.Qualifications).Not.LazyLoad(); } I'm trying various combinations of cascade and inverse settings but can never get there. If i have no cascades and no inverse i get duplicated entities in my collections. Setting inverse on one side makes the duplication go away but when i try to delete a qualification i get a 'deleted object would be re-saved by cascade'. How do i do this? Should i be responsible for clearing the associations of each object i delete?

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• Core Data 1-to-many relationship: List all related objects as section header in UITableView

  - by Snej

  Hi: I struggle with Core Data on the iPhone about the following: I have a 1-to-many relationship in Core Data. Assume the entities are called recipe and category. A category can have many recipes. I accomplished to get all recipes listed in a UITableView with section headers named after the category. What i want to achieve is to list all categories as section header, even those which have no recipe: category1 <--- this one should be displayed too category2 recipe_x recipe_y category3 recipe_z NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init]; NSEntityDescription *entity = [NSEntityDescription entityForName:@"Recipe" inManagedObjectContext:managedObjectContext]; [fetchRequest setEntity:entity]; [fetchRequest setFetchBatchSize:10]; NSSortDescriptor *sortDescriptor1 = [[NSSortDescriptor alloc] initWithKey:@"category.categoryName" ascending:YES]; NSSortDescriptor *sortDescriptor2 = [[NSSortDescriptor alloc] initWithKey:@"recipeName" ascending:YES]; NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor1,sortDescriptor2, nil]; [fetchRequest setSortDescriptors:sortDescriptors]; NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:managedObjectContext sectionNameKeyPath:@"category.categoryName" cacheName:@"Recipes"]; What is the most elegant way to achieve this with core data?

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• Empty data problem - data layer or DAL?

  - by luckyluke

  I designing the new App now and giving the following question a lot of thought. I consume a lot of data from the warehouse, and the entities have a lot of dictionary based values (currency, country, tax-whatever data) - dimensions. I cannot be assured though that there won't be nulls. So I am thinking: create an empty value in each of teh dictionaries with special keyID - ie. -1 do the ETL (ssis) do the correct stuff and insert -1 where it needs to let the DAL know that -1 is special (Static const whatever thing) don't care in the code to check for nullness of dictionary entries because THEY will always have a value But maybe I should be thinking: import data AS IS let the DAL do the thinking using empty record Pattern still don't care in the code because business layer will have what it needs from DAL. I think is more of a approach thing but maybe i am missing something important here... What do You think? Am i clear? Please don't confuse it with empty record problem. I do use emptyCustomer think all the time and other defaults too.

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• FlashBuilder 4 and Zend Framework error

  - by sig

  I am trying to use adobe flash builder 4 with a php service. I had it set up an older macbook running leopard, but just tried to set it up on my new laptop running snow leopard. I did all the same steps.. set the Flex Server to be PHP, set the web root and url. Then I go to Data-Connect To PHP and point it to a php file I have in my web root. It says it needs to install Zend, and claims it does so successfully, but then when I try to continue, I get an error. I don't understand.. this same setup works on my older laptop. (Yes, I checked the amf.production was false) Unable to retrieve operations and entities from the file Make sure that Zend Framework is installed correctly and the parameter "amf.production" is not set to true in the amf_config.ini file located in the project output folder. false), true);$default_config-merge(new Zend_Config_Ini($configfile, 'zendamf'));$default_config-setReadOnly();$amf = $default_config-amf;// Store configuration in the registryZend_Registry::set("amf-config", $amf);// Initialize AMF Server$server = new Zend_Amf_Server();$server-setProduction($amf-production);if(isset($amf-directories)) { $dirs = $amf-directories-toArray(); foreach($dirs as $dir) { // get the first character of the path. // If it does not start with slash then it implies that the path is relative to webroot. Else it will be treated as absolute path $length = strlen($dir); $firstChar = $dir; if($length = 1) $firstChar = $dir[0]; if($firstChar != "/"){ // if the directory is ./ path then we add the webroot only. if($dir == "./"){ $server-addDirectory($webroot); }else{ $tempPath = $webroot . "/" . $dir; $server-addDirectory($tempPath); } }else{ $server-addDirectory($dir); } }}// Initialize introspector for non-productionif(!$amf-production) { $server-setClass('Zend_Amf_Adobe_Introspector', '', array("config" = $default_config, "server" = $server)); $server-setClass('Zend_Amf_Adobe_DbInspector', '', array("config" = $default_config, "server" = $server));}// Handle requestecho $server-handle();

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• Dynamically add User Controls to a Silverlight 4 page

  - by PilotBob

  I am building an iGoogle like "dashboard" for our application with silverlight 4. Each users dashboard (which snapins and their positions) will be stored in the database. Each snap in is a user control, for example... AwesomeSnapin.xaml. On the dashboard page in silverlight I am retrieving the users dashboard which is a collection of snapin objects which include the information on the snapin. I can store the name of the page or the class or whatever is needed. I have the following code which loops through the collection of snapins to add them to the dashboard page. In testing I have just hard coded a single snapin item. Here is the prototype code: foreach (var UserSnapin in op.Entities) { UserControl uc = new AmsiSL.eFinancials.BudgetCheck(); Canvas.SetLeft(uc, UserSnapin.PositionLeft); Canvas.SetTop(uc, UserSnapin.PositionTop); Layout.Children.Add(uc); MessageBox.Show(String.Format("Added {0}",UserSnapin.Snapin.Name)); } The above works fine... but of course adds the BudgetCheck snapin for every item that is defined for the users dashboard. Of course the messagebox is for debugging purposes only. How would I change line 3 of that to load the user control class (using classname or xaml path whichever is better) based on the data in the collection.

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• What is the correct way to create dynamic javascript in ASP.net MVC2?

  - by sabbour

  I'm creating a Google Maps partial view/user control in my project that is passed a strongly typed list of objects containing latitude and longitude values. Currently, this is the code I have for the partial: <%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<IEnumerable<Project.Models.Entities.Location>>" %> <!-- Place for google to put the map --> <div id="report_map_canvas" style="width: 100%; height: 728px; margin-bottom: 2px;"> </div> <script type='text/javascript'> google.load("maps", "2"); $(document).ready(initializeMap); function initializeMap() { if (GBrowserIsCompatible()) { var map = new GMap2(document.getElementById('report_map_canvas')); map.setCenter(new GLatLng(51.5, -0.1167), 2); <% foreach (var item in Model) { %> map.addOverlay(new GMarker(new GLatLng('<%= Html.Encode(item.latitude)%>','<%= Html.Encode(item.longitude)%>'),{ title: '<%= Html.Encode(String.Format("{0:F}",item.speed)) %> km/h '})); <% } %> map.setUIToDefault(); } } </script> Is it right to dynamically create the javascript file this way by looping over the list and emitting javascript? Is there a better way to do it?

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• Declaring functors for comparison ??

  - by Mr.Gando

  Hello, I have seen other people questions but found none that applied to what I'm trying to achieve here. I'm trying to sort Entities via my EntityManager class using std::sort and a std::vector<Entity *> /*Entity.h*/ class Entity { public: float x,y; }; struct compareByX{ bool operator()(const GameEntity &a, const GameEntity &b) { return (a.x < b.x); } }; /*Class EntityManager that uses Entitiy*/ typedef std::vector<Entity *> ENTITY_VECTOR; //Entity reference vector class EntityManager: public Entity { private: ENTITY_VECTOR managedEntities; public: void sortEntitiesX(); }; void EntityManager::sortEntitiesX() { /*perform sorting of the entitiesList by their X value*/ compareByX comparer; std::sort(entityList.begin(), entityList.end(), comparer); } I'm getting a dozen of errors like : error: no match for call to '(compareByX) (GameEntity* const&, GameEntity* const&)' : note: candidates are: bool compareByX::operator()(const GameEntity&, const GameEntity&) I'm not sure but ENTITY_VECTOR is std::vector<Entity *> , and I don't know if that could be the problem when using the compareByX functor ? I'm pretty new to C++, so any kind of help is welcome.

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• Core-data: when accessing a relationship, the count method on NSSet fails

  - by lordsandwich

  I'm trying to access a relationship (one to many) programatically. My Data model contains an NSManagedEntity called language (with a two string attributes) with a relationship to an entity called WordCategory (one-to-many). I use an NSFetchRequest to get all the Language entities. that works fine. I get the valueForKey for the relationship and that works fine. I can work with its objects. However, when I try to send the message count to the NSSet that stores the WordCategory objects I get a In other words, this line works: NSLog(@"word category count %@",[[wordCategory anyObject] valueForKey:@"name"]); This one doesn't: NSLog(@"word category count %@",[wordCategory count] I get a the message: EXC_BAD_ACCESS in the debugger. Here's the rest of the code: NSManagedObjectContext *moc = [myAppDelegate managedObjectContext]; NSFetchRequest *request = [[NSFetchRequest alloc] init]; [request setEntity:[NSEntityDescription entityForName:@"Language" inManagedObjectContext:moc]]; NSError *error = nil; NSArray *results = [moc executeFetchRequest:request error: &error]; if (error) { [NSApp presentError:error]; return; } NSManagedObject *obj = [results objectAtIndex:0]; NSSet *wordCategory = [obj valueForKey:@"category"]; NSLog(@"word category count %@",[wordCategory count]); I'll appreciate any light than anybody can shed in this mystery. Thanks for your help!

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• Update Related Entity Of Detached Entity

  - by Hemslingo

  I'm having an issue updating an entity with multiple related entities. I've got a very simple model which consists of an article entity and a list of categories the article can be related to. You can choose from a check box list which of these categories are associated to it...which works fine. The problem crops up when I actually come to update an existing entity using the dbContext. As I am updating this entity, I have already detached it from the context ready to re-attach it later so the update can execute properly. I can see that after I posting the model, the category(s) are being added to the article entity just fine and it looks like it updates in the repository with no errors occurring. When I look in the database the article has updated as normal but the category(s) have not. Here is my (simplified) update code... public virtual bool Attach(T entity) { _dbContext.Entry(entity).State = EntityState.Modified; _dbSet.Attach(entity); return this.Commit(); } Any help will be much appreciated.

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• How can i ignore map property in NHibernate with setter

  - by Emilio Montes

  i need ignore map property with setter in NHibernate, because the relationship between entities is required. this is my simple model public class Person { public virtual Guid PersonId { get; set; } public virtual string FirstName { get; set; } public virtual string SecondName { get; set; } //this is the property that do not want to map public Credential Credential { get; set; } } public class Credential { public string CodeAccess { get; set; } public bool EsPremium { get; set; } } public sealed class PersonMap : ClassMapping<Person> { public PersonMap() { Table("Person"); Cache(x => x.Usage(CacheUsage.ReadWrite)); Id(x => x.Id, m => { m.Generator(Generators.GuidComb); m.Column("PersonId"); }); Property(x => x.FirstName, map => { map.NotNullable(true); map.Length(255); }); Property(x => x.SecondName, map => { map.NotNullable(true); map.Length(255); }); } } I know that if I leave the property Credential {get;} I was not going to take the map of NHibernate, but I need to set the value. Thanks in advance.

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• Execute SQL on CSV files via JDBC

  - by Markos Fragkakis

  Dear all, I need to apply an SQL query to CSV files (comma-separated text files). My SQL is predefined from another tool, and is not eligible to change. It may contain embedded selects and table aliases in the FROM part. For my task I have found two open-source (this is a project requirement) libraries that provide JDBC drivers: CsvJdbc XlSQL JBoss Teiid Create an Apache Derby DB, load all CSVs as tables and execute the query. These are the problems I encountered: it does not accept the syntax of the SQL (it uses internal selects and table aliases). Furthermore, it has not been maintained since 2004. I could not get it to work, as it has as dependency a SAX Parser that causes exception when parsing other documents. Similarly, no change since 2004. Have not checked if it supports the syntax, but seems like an overhead. It needs several entities defines (Virtual Databases, Bindings). From the mailing list they told me that last release supports runtime creation of required objects. Has anyone used it for such simple task (normally it can connect to several types of data, like CSV, XML or other DBS and create a virtual, unified one)? Can this even be done easily? From the 4 things I considered/tried, only 3 and 4 seem to me viable. Any advice on these, or any other way in which I can query my CSV files? Cheers

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• Neural Network settings for fast training

  - by danpalmer

  I am creating a tool for predicting the time and cost of software projects based on past data. The tool uses a neural network to do this and so far, the results are promising, but I think I can do a lot more optimisation just by changing the properties of the network. There don't seem to be any rules or even many best-practices when it comes to these settings so if anyone with experience could help me I would greatly appreciate it. The input data is made up of a series of integers that could go up as high as the user wants to go, but most will be under 100,000 I would have thought. Some will be as low as 1. They are details like number of people on a project and the cost of a project, as well as details about database entities and use cases. There are 10 inputs in total and 2 outputs (the time and cost). I am using Resilient Propagation to train the network. Currently it has: 10 input nodes, 1 hidden layer with 5 nodes and 2 output nodes. I am training to get under a 5% error rate. The algorithm must run on a webserver so I have put in a measure to stop training when it looks like it isn't going anywhere. This is set to 10,000 training iterations. Currently, when I try to train it with some data that is a bit varied, but well within the limits of what we expect users to put into it, it takes a long time to train, hitting the 10,000 iteration limit over and over again. This is the first time I have used a neural network and I don't really know what to expect. If you could give me some hints on what sort of settings I should be using for the network and for the iteration limit I would greatly appreciate it. Thank you!

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• Objective-C: fetchManagedObjectsForEntity problem

  - by Meko

  Hi.I am trying to get value from CoreData entity name Person with predicate and then comparing with new data in dictionary.But it it returns every time 0 .And it creates about 5 person with same name. NSPredicate *predicate = [NSPredicate predicateWithFormat:@"userName == %@",[flickr usernameForUserID:@"owner"]]; peopleList = (NSMutableArray *)[flickr fetchManagedObjectsForEntity:@"Person" withPredicate:predicate]; NSEnumerator *enumerator = [peopleList objectEnumerator]; Person *person; BOOL exists = FALSE; while (person = [enumerator nextObject]) { NSLog(@" Person is: %@ ", person.userName); NSLog(@"Person ID IS %@",person.userID); NSLog(@"Dict ID is %@",[dict objectForKey:@"owner"]); if([person.userID isEqualToString:[dict objectForKey:@"owner"]]) { exists = TRUE; NSLog(@"-- Person Exists : %@--", person.userName); [newPhoto setPerson:person]; } } Here peopleList returns 0 and the enumerator also 0 and it does not use if and not comparing.In my entity I have Person and Photo entities.In Person I have userName and userID attributes and also one-to many relationship with Photo entity. I think problem in predicate but i cant figure out it .

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• Why does the Combo.SelectedValue get lost after some time

  - by tzup

  So I have this asp:DropDownList on a page. It renders like this (in IE7): <select name="ctl00$cphFilter$cbLista" onchange="javascript:setTimeout('__doPostBack(\'ctl00$cphFilter$cbLista\',\'\')', 0)" id="ctl00_cphFilter_cbLista" class="agsSelect"> <option selected="selected" value="4350">A</option> <option value="4352">B</option> <option value="4349">C</option> <option value="4348">D</option> And then I have a grid and a button on the same page. When the user clicks the button the selected item of the dropdown is read (well a datasource object reads it) and the grid does a databind after a trip to a DB where it gets some data based on that selected value. This works fine most of the time. However sometimes, the selection in the dropdownlist seems to get lost even though the rendered page says the A is the selected item. The datasource object is defined like this: <asp:ObjectDataSource ID="dsVM" runat="server" EnablePaging="False" SelectMethod="Select" SortParameterName="sort" TypeName="X.Business.Entities.LPVM.BE"> <SelectParameters> <asp:ControlParameter Name="listaId" Type="Int32" ControlID="cphFilter$cbLista" PropertyName="SelectedValue" /> </SelectParameters> </asp:ObjectDataSource> Any ideas why the grid would reload its data with a select parameter that is 0 instead of the selected value of the dropdownlist? EDIT Suppose the dropdownlist is bound, the user selected B and the grid is bound as well and shows the right data. Now, I wait 2 minutes and I click the Refresh button. Surprisingly, at this particular moment the dropdownlist.SelectedValue (which I already know it was 4352 before I clicked because that's how it looks in the rendered page) is actually an empty string. Where did the value go?

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• How to route tree-structured URLs with ASP.NET Routing?

  - by Venemo

  Hello Everyone, I would like to achieve something very similar to this question, with some enhancements. There is an ASP.NET MVC web application. I have a tree of entities. For example, a Page class which has a property called Children, which is of type IList<Page>. (An instance of the Page class corresponds to a row in a database.) I would like to assign a unique URL to every Page in the database. I handle Page objects with a Controller called PageController. Example URLs: http://mysite.com/Page1/ http://mysite.com/Page1/SubPage/ http://mysite.com/Page/ChildPage/GrandChildPage/ You get the picture. So, I'd like every single Page object to have its own URL that is equal to its parent's URL plus its own name. In addition to that, I also would like the ability to map a single Page to the / (root) URL. I would like to apply these rules: If a URL can be handled with any other route, or a file exists in the filesystem in the specified URL, let the default URL mapping happen If a URL can be handled by the virtual path provider, let that handle it If there is no other, map the other URLs to the PageController class I also found this question, and also this one and this one, but they weren't of much help, since they don't provide an explanation about my first two points. I see the following possible soutions: Map a route for each page invidually. This requires me to go over the entire tree when the application starts, and adding an exact match route to the end of the route table. I could add a route with {*path} and write a custom IRouteHandler that handles it, but I can't see how could I deal with the first two rules then, since this handler would get to handle everything. So far, the first solution seems to be the right one, because it is also the simplest. I would really appreciate your thoughts on this. Thank you in advance!

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• How to create database records for a financial year

  - by David A Gibson

  Hello, I need to create entities (specifically contracts) in a database table that are associated with a financial year. These contracts will be applied to projects. Any contract variation will be recorded by creating a new contract record for the same financial year but the original will remain associated with the project as a history. The projects can last several years and so at any one time a project will have a live contract record for each year as well as any number of historic contracts for that year. All of which is incidental but I'm trying to provide some context. If the contracts where for the year - it would be easy and I'd just store the Year either as a date field with the 1st of January or just an Integer. However the contracts run for financial years and I don't know how to approach this. I don't want a separate table containing the financial years as I don't want the users to have to maintain this. I don't want to store the financial year as a string "2009/2010" as this is not ideal for sorting/extracting the data. Any ideas will be helpful, my best so far is to have starting and ending year in 2 columns and just "KNOW" that starting is April of the year etc Thanks

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• Are there any ASP.NET MVC subscription-based starter kits or examples?

  - by Wayne M

  Basically something that handles the low-level "plumbing" code for a subscription-based service. I see a lot of things dealing with basic membership, but nothing that handles the subscription aspect (recurring billing, automated jobs for setting up billing, notification for billing, etc). This might be the one thing that keeps me from using ASP.NET MVC for my SaaS idea, since it would take a fair amount of development time to write my own; if I go with my other option, Ruby on Rails, I can buy a kit that does all of this for $250. I haven't found anything even remotely close to this for .NET - all of the SaaS sample apps I've seen are more like StackOverflow et all where you have one site that multiple people log on to, not the web application model where you have subscribers who are billed monthly, each of whom has users and other entities (e.g. Customers, Tasks, etc) for their own site. Is there anything similar for ASP.NET, or some kind of guidelines for writing my own if I have to, so I don't waste too much time? As a startup that means that I'm doing all the coding myself. I've found this, but it seems to only be for billing and didn't seem to have much (any?) documentation on exactly how to set it up.

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• Learning Hibernate: too many connections

  - by stivlo

  I'm trying to learn Hibernate and I wrote the simplest Person Entity and I was trying to insert 2000 of them. I know I'm using deprecated methods, I will try to figure out what are the new ones later. First, here is the class Person: @Entity public class Person { private int id; private String name; @Id @GeneratedValue(strategy = GenerationType.TABLE, generator = "person") @TableGenerator(name = "person", table = "sequences", allocationSize = 1) public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } } Then I wrote a small App class that insert 2000 entities with a loop: public class App { private static AnnotationConfiguration config; public static void insertPerson() { SessionFactory factory = config.buildSessionFactory(); Session session = factory.getCurrentSession(); session.beginTransaction(); Person aPerson = new Person(); aPerson.setName("John"); session.save(aPerson); session.getTransaction().commit(); } public static void main(String[] args) { config = new AnnotationConfiguration(); config.addAnnotatedClass(Person.class); config.configure("hibernate.cfg.xml"); //is the default already new SchemaExport(config).create(true, true); //print and execute for (int i = 0; i < 2000; i++) { insertPerson(); } } } What I get after a while is: Exception in thread "main" org.hibernate.exception.JDBCConnectionException: Cannot open connection Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Too many connections Now I know that probably if I put the transaction outside the loop it would work, but mine was a test to see what happens when executing multiple transactions. And since there is only one open at each time, it should work. I tried to add session.close() after the commit, but I got Exception in thread "main" org.hibernate.SessionException: Session was already closed So how to solve the problem?

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• Types issue in F#

  - by Andry

  Hello! In my ongoing adventure deep diving into f# I am understanding a lot of this powerful language but there are things that I still do not understand so clearly. One of the most important issues I need to master is types. Well the book I am reading is very straight forward and introduces entities and main functionalities with a direct approach. The first thing I could get start with is types. It introduces the main types as list, option, tuples, and so on... It is clearly underlined that all these types are IMMUTABLE for many reasons regarding functional programming and data consistance in functional programing. Well, no problems until now... But now I am getting started with Concrete Types... Well... I have problems in managing with types like list, option, tuples, types created through new operator and concrete types created using type keyword (for abbreviations, concrete types...). So my question is: how can I efficently catalogue/distinguish all types of data in f#???? I can create a perfect separation among types in C#, VB.NET... FOr example in VB.NET there are value and reference types while in C# there are only references and also int, double are treated as objects (they are objects while in VB.NET a value type is not a object and there is a split in types for this reason). Well in F# I cannot create such differences among types in the language. Can you help me? I hope I was clear.

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• How does a java web project architecture look like without EJB3 ?

  - by Hendrik

  A friend and I are building a fairly complex website based on java. (PHP would have been more obvious but we chose for java because the educational aspect of this project is important to us) We have already decided to use JSF (with richfaces) for the front end and JPA for the backend and so far we have decided not to use EJB3 for the business layer. The reason we've decided not to use EJB3 is because - and please correct me if I am wrong - if we use EJB3 we can only run it on a full blown java application server like jboss and if we don't use EJB3 we can still run it on a lightweight server like tomcat. We want to keep speed and cost of our future web server in mind. So far i've worked on two JEE projects and both used the full stack with web business logic factories/persistence service entities with every layer a seperate module. Now here is my question, if you dont use EJB3 in the business logic layer. What does the layer look like? Please tell what is common practice when developing java web projects without ejb3? Do you think business logic layer can be thrown out altogether and have business logic in the backing beans? If you keep the layer, do you have all business methods static? Or do you initialize each business class as needed in the backing beans in every session as needed?

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• Hibernate triggering constraint violations using orphanRemoval

  - by ptomli

  I'm having trouble with a JPA/Hibernate (3.5.3) setup, where I have an entity, an "Account" class, which has a list of child entities, "Contact" instances. I'm trying to be able to add/remove instances of Contact into a List<Contact> property of Account. Adding a new instance into the set and calling saveOrUpdate(account) persists everything lovely. If I then choose to remove the contact from the list and again call saveOrUpdate, the SQL Hibernate seems to produce involves setting the account_id column to null, which violates a database constraint. What am I doing wrong? The code below is clearly a simplified abstract but I think it covers the problem as I'm seeing the same results in different code, which really is about this simple. SQL: CREATE TABLE account ( INT account_id ); CREATE TABLE contact ( INT contact_id, INT account_id REFERENCES account (account_id) ); Java: @Entity class Account { @Id @Column public Long id; @OneToMany(cascade = CascadeType.ALL, orphanRemoval = true) @JoinColumn(name = "account_id") public List<Contact> contacts; } @Entity class Contact { @Id @Column public Long id; @ManyToOne(optional = false) @JoinColumn(name = "account_id", nullable = false) public Account account; } Account account = new Account(); Contact contact = new Contact(); account.contacts.add(contact); saveOrUpdate(account); // some time later, like another servlet request.... account.contacts.remove(contact); saveOrUpdate(account); Result: UPDATE contact SET account_id = null WHERE contact_id = ? Edit #1: It might be that this is actually a bug http://opensource.atlassian.com/projects/hibernate/browse/HHH-5091

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• What is the difference between cubes and the Unified Dimensional Model (if any)?

  - by ngm

  I'm currently researching SQL Server 2008 as a business intelligence solution, and currently looking at Analysis Services (and I'm pretty new to business intelligence as a whole...) I'm a bit confused by some of the terms in SSAS, particularly the conceptual differences between cubes and MS's Unified Dimensional Model. I believe that a cube in SSAS is basically an OLAP cube -- dimensions, measures, something that sits between the underlying data source and a business user. But then that's kind of what I understand UDM to be as well. The docs for SQL Server 2005 seem to suggest as much: "A cube is essentially synonymous with a Unified Dimensional Model (UDM)". But then the SQL Server 2008 pages sort of suggest that UDM is a wrapper for both multidimensional data (cubes) and relational data: "Use the Unified Dimensional Model to provide one consolidated business view for relational and multidimensional data that includes business entities, business logic, calculations, and metrics." This blog post suggests similarly: "UDM provides a single dimensional model for all OLAP analysis and relational reporting needs. So you can use either MDX or SQL" Is UDM something that sits above cubes? Or are they the same thing? I presume I would develop cubes with the Cube Designer application; what would I develop a UDM with?

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• Extending EF4 SQL Generation

  - by Basiclife

  Hi, We're using EF4 in a fairly large system and occasionally run into problems due to EF4 being unable to convert certain expressions into SQL. At present, we either need to do some fancy footwork (DB/Code) or just accept the performance hit and allow the query to be executed in-memory. Needless to say neither of these is ideal and the hacks we've sometimes had to use reduce readability / maintainability. What we would ideally like is a way to extend the SQL generation capabilities of the EF4 SQL provider. Obviously there are some things like .Net method calls which will always have to be client-side but some functionality like date comparisons (eg Group by weeks in Linq to Entities ) should be do-able. I've Googled but perhaps I'm using the wrong terminology as all I get is information about the new features of EF4 SQL Generation. For such a flexible and extensible framework, I'd be surprised if this isn't possible. In my head, I'm imagining inheriting from the [SQL 2008] provider and extending it to handle additional expressions / similar in the expression tree it's given to convert to SQL. Any help/pointers appreciated. We're using VS2010 Ultimate, .Net 4 (non-client profile) and EF4. The app is in ASP.Net and is running in a 64-Bit environment in case it makes a difference.

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• nhibernate not taking mappings from assembly

  - by cvista

  Hi I'm using fnh and castle nhib facility. I followed the advice from mike hadlow here: http://mikehadlow.blogspot.com/2009/01/integrating-fluent-nhibernate-and.html here is my FluentNHibernateConfigurationBuilder: public Configuration GetConfiguration(IConfiguration facilityConfiguration) { var defaultConfigurationBuilder = new DefaultConfigurationBuilder(); var configuration = defaultConfigurationBuilder.GetConfiguration(facilityConfiguration); configuration.AddMappingsFromAssembly(typeof(User).Assembly); return configuration; } i know the facility is picking it up as i can break inside that method and it steps through. however, when it's done, non of the mappings are created and i get the following error when i try to save an entity: No persister for: IsItGd.Model.Entities.User here is my user class: //simple model of web user public class User { public virtual int Id { get; set; } public virtual string FullName { get; set; } } and here is the mapping: public class UserMap : ClassMap<User> { public UserMap() { Id(x=>x.Id); Map(x=>x.FullName); } } i really can't see what the problem is. the strange thing is - is that if i use automapping it picks everything up - but i don't want to use automapping as i can't do certain things in that scenario. any clues? w://

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