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  • NHibernate : Root collection with an root object

    - by Daniel
    Hi, I want to track a list of root objects which are not contained by any element. I want the following pseudo code to work: IList<FavoriteItem> list = session.Linq<FavoriteItem>().ToList(); list.Add(item1); list.Add(item2); list.Remove(item3); list.Remove(item4); var item5 = list.First(i => i.Name = "Foo"); item5.Name = "Bar"; session.Save(list); This should automatically insert item1 and item2, delete item3 and item3 and update item5 (i.e. I don't want to call sesssion.SaveOrUpdate() for all items separately. Is it possible to define a pseudo entity that is not associated with a table? For example I want to define the class Favorites and map 2 collection properties of it and than I want to write code like this: var favs = session.Linq<Favorites>(); favs.FavoriteColors.Add(new FavoriteColor(...)); favs.FavoriteMovies.Add(new FavoriteMovie(...)); session.SaveOrUpdate(favs); FavoriteColors and FavoriteMovies are the only properties of the Favorites class and are of type IList and IList. I do only want to persist the these two collection properties but not the Favorites class. Any help is much appreciated.

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  • Complicated .NET factory design

    - by Tom W
    Hello SO; I'm planning to ask a fairly elaborate question that is also something of a musing here, so bear with me... I'm trying to design a factory implementation for a simulation application. The simulation will consist of different sorts of entities i.e. it is not a homogenous simulation in any respect. As a result, there will be numerous very different concrete implementations and only the very general properties will be abstracted at the top level. What I'd like to be able to do is create new simulation entities by calling a method on the model with a series of named arguments representing the parameters of the entity, and have the model infer what type of object is being described by the inbound parameters (from the names of the parameters and potentially the sequence they occur in) and call a factory method on the appropriate derived class. For example, if I pass the model a pair of parameters (Param1=5000, Param2="Bacon") I would like it to infer that the names Param1 and Param2 'belong' to the class "Blob1" and call a shared function "getBlob1" with named parameters Param1:=5000, Param2:="Bacon" whereas if I pass the model (Param1=5000, Param3=50) it would call a similar factory method for Blob2; because Param1 and Param3 in that order 'belong' to Blob2. I foresee several issues to resolve: Whether or not I can reflect on the available types with string parameter names and how to do this if it's possible Whether or not there's a neat way of doing the appropriate constructor inference from the combinatoric properties of the argument list or whether I'm going to have to bodge something to do it 'by hand'. If possible I'd like the model class to be able to accept parameters as parameters rather than as some collection of keys and values, which would require the model to expose a large number of parametrised methods at runtime without me having to code them explicitly - presumably one for every factory method available in the relevant namespace. What I'm really asking is how you'd go about implementing such a system, rather than whether or not it's fundamentally possible. I don't have the foresight or experience with .NET reflection to be able to figure out a way by myself. Hopefully this will prove an informative discussion.

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  • Play! 1.2.5 with mongodb | Model Validation not happening

    - by TGV
    I have a simple User model whose fields are annotated with play validation annotations and morphia annotations like below. import play.data.validation.*; import play.modules.morphia.Model; import com.google.code.morphia.annotations.*; @Entity public class User extends Model{ @Id @Indexed(name="USERID", unique=true) public ObjectId userId; @Required public String userName; @Email @Indexed(name="USEREMAIL", unique=true) @Required public String userEmail; } Now I have a service which has a CreateNewUser method responsible for persisting the data. I have used Morphia plugin for the dao support. But the problem is that User Document gets persisted in mongo-db even if userName or userEmail is NULL. Also @Email validation does not happen // Below code is in app/controllers/Application.java User a = new User(); a.userName = "user1"; // calling bean to create user, userService is in app/service/UserService userService.createNewUser(a); It does not work even after adding @valid and validation.hasErrors() check.Below code is in app/service/UserService public void createNewUser(@Valid User user) { if (Validation.hasErrors()) { System.out.println("has errors"); } else { // TODO Auto-generated method stub userDao.save(user); } }

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  • Batch insert mode with hibernate and oracle: seems to be dropping back to slow mode silently

    - by Chris
    I'm trying to get a batch insert working with Hibernate into Oracle, according to what i've read here: http://docs.jboss.org/hibernate/core/3.3/reference/en/html/batch.html , but with my benchmarking it doesn't seem any faster than before. Can anyone suggest a way to prove whether hibernate is using batch mode or not? I hear that there are numerous reasons why it may silently drop into normal mode (eg associations and generated ids) so is there some way to find out why it has gone non-batch? My hibernate.cfg.xml contains this line which i believe is all i need to enable batch mode: <property name="jdbc.batch_size">50</property> My insert code looks like this: List<LogEntry> entries = ..a list of 100 LogEntry data classes... Session sess = sessionFactory.getCurrentSession(); for(LogEntry e : entries) { sess.save(e); } sess.flush(); sess.clear(); My 'logentry' class has no associations, the only interesting field is the id: @Entity @Table(name="log_entries") public class LogEntry { @Id @GeneratedValue public Long id; ..other fields - strings and ints... However, since it is oracle, i believe the @GeneratedValue will use the sequence generator. And i believe that only the 'identity' generator will stop bulk inserts. So if anyone can explain why it isn't running in batch mode, or how i can find out for sure if it is or isn't in batch mode, or find out why hibernate is silently dropping back to slow mode, i'd be most grateful. Thanks

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  • Google appEngine: 404 when accesing /_ah/api

    - by jfu
    I try to build a very simple GAE application, using eclipse and the Google Plugin for Eclipse. I've generated some Endpoint from an @Entity class, then I've generated Cloud Endpoint Client library. After that I've started the appEngine project (within eclipse, on the embedded jetty server). When I try to access /_ah/api I get the following issue: HTTP ERROR 500 Problem accessing /_ah/api/. Reason: Failed to retrieve API configs with status: 404 Caused by: java.io.IOException: Failed to retrieve API configs with status: 404 at com.google.api.server.spi.tools.devserver.ApiServlet.getApiConfigSources(ApiServlet.java:102) at com.google.api.server.spi.tools.devserver.ApiServlet.initConfigsIfNecessary(ApiServlet.java:67) at com.google.api.server.spi.tools.devserver.RestApiServlet.service(RestApiServlet.java:117) at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166) at com.google.appengine.api.socket.dev.DevSocketFilter.doFilter(DevSocketFilter.java:74) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) at com.google.appengine.tools.development.ResponseRewriterFilter.doFilter(ResponseRewriterFilter.java:123) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:34) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:63) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:125) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) at com.google.appengine.tools.development.DevAppServerModulesFilter.doDirectRequest(DevAppServerModulesFilter.java:368) at com.google.appengine.tools.development.DevAppServerModulesFilter.doDirectModuleRequest(DevAppServerModulesFilter.java:351) at com.google.appengine.tools.development.DevAppServerModulesFilter.doFilter(DevAppServerModulesFilter.java:116) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388) at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216) at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182) at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765) at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418) What am I doing wrong?

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  • What are the hibernate annotations used to persist a Map with an enumerated type as a key?

    - by Jason Novak
    I am having trouble getting the right hibernate annotations to use on a Map with an enumerated class as a key. Here is a simplified (and extremely contrived) example. public class Thing { public String id; public Letter startLetter; public Map<Letter,Double> letterCounts = new HashMap<Letter, Double>(); } public enum Letter { A, B, C, D } Here are my current annotations on Thing @Entity public class Thing { @Id public String id; @Enumerated(EnumType.STRING) public Letter startLetter; @CollectionOfElements @JoinTable(name = "Thing_letterFrequencies", joinColumns = @JoinColumn(name = "thingId")) @MapKey(columns = @Column(name = "letter", nullable = false)) @Column(name = "count") public Map<Letter,Double> letterCounts = new HashMap<Letter, Double>(); } Hibernate generates the following DDL to create the tables for my MySql database create table Thing (id varchar(255) not null, startLetter varchar(255), primary key (id)) type=InnoDB; create table Thing_letterFrequencies (thingId varchar(255) not null, count double precision, letter tinyblob not null, primary key (thingId, letter)) type=InnoDB; Notice that hibernate tries to define letter (my map key) as a tinyblob, however it defines startLetter as a varchar(255) even though both are of the enumerated type Letter. When I try to create the tables I see the following error BLOB/TEXT column 'letter' used in key specification without a key length I googled this error and it appears that MySql has issues when you try to make a tinyblob column part of a primary key, which is what hibernate needs to do with the Thing_letterFrequencies table. So I would rather have letter mapped to a varchar(255) the way startLetter is. Unfortunately, I've been fussing with the MapKey annotation for a while now and haven't been able to make this work. I've also tried @MapKeyManyToMany(targetEntity=Product.class) without success. Can anyone tell me what are the correct annotations for my letterCounts map so that hibernate will treat the letterCounts map key the same way it does startLetter?

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  • ADO.NET Data Services Media type requires a ';' character before a parameter definition.

    - by idahosaedokpayi
    I am experimenting with ADO.NET and I am seeing this error on the second attempt to browse the service: <?xml version="1.0" encoding="utf-8" standalone="yes" ?> <error xmlns="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata"> <code /> <message xml:lang="en-US">Media type requires a ';' character before a parameter definition.</message> </error> The first attempt is normal. I am working with an exactly identical service on an internal development network and it is fine. I am including my connection string: <add name="J4Entities" connectionString="metadata=res://*;provider=System.Data.SqlClient;provider connection string=&quot;Data Source=MNSTSQL01N;Initial Catalog=J4;Integrated Security=True;MultipleActiveResultSets=True&quot;" providerName="System.Data.EntityClient"/> and my Data service class: using System; using System.Data.Services; using System.Collections.Generic; using System.Linq; using System.ServiceModel.Web; public class Data : DataService< J4Model.J4Entities > { // This method is called only once to initialize service-wide policies. public static void InitializeService(IDataServiceConfiguration config) { // TODO: set rules to indicate which entity sets and service operations are visible, updatable, etc. // Examples: config.SetEntitySetAccessRule("*", EntitySetRights.AllRead); // config.SetServiceOperationAccessRule("MyServiceOperation", ServiceOperationRights.All); } } Is there something obvious I am not doing?

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  • Injecting the application TransactionManager into a JPA EntityListener

    - by nodje
    I want to use the JPA EntityListener to support spring security ACLs. On @PostPersist events, I create a permission corresponding to the persisted entity. I need this operation to participate to the current Transaction. For this to happen I need to have a reference to the application TransactionManager in the EntityListener. The problem is, Spring can't manage the EntityListener as it is created automatically when EntityManagerFactory is instantiated. And in a classic Spring app, the EntityManagerFactory is itself created during the TransactioManager instantiation. <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager"> <property name="entityManagerFactory" ref="entityManagerFactory" /> </bean> So I have no way to inject the TransactionManager with the constructor, as it is not yet instantiated. Making the EntityManager a @Component create another instance of the EntityManager. Implementing InitiliazingBean and using afterPropertySet() doesn't work as it's not a Spring managed bean. Any idea would be helpful as I'm stuck and out of ideas.

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  • What is the correct approach to using GWT with persistent objects?

    - by dankilman
    Hi, I am currently working on a simple web application through Google App engine using GWT. It should be noted that this is my first attempt at such a task. I have run into to following problem/dilema: I have a simple Class (getters/setters and nothing more. For the sake of clarity I will refer to this Class as DataHolder) and I want to make it persistent. To do so I have used JDO which required me to add some annotations and more specifically add a Key field to be used as the primary key. The problem is that using the Key class requires me to import com.google.appengine.api.datastore.Key which is ok on the server side, but then I can't use DataHolder on the client side, because GWT doesn't allow it (as far as I know). So I have created a sister Class ClientDataHolder which is almost identical, though it doesn't have all the JDO annotations nor the Key field. Now this actually works but It feels like I'm doing something wrong. Using this approach would require maintaining to separate classes for each entity I wish to have. So my question is: Is there a better way of doing this? Thank you.

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  • Python + Expat: Error on &#0; entities

    - by clacke
    I have written a small function, which uses ElementTree and xpath to extract the text contents of certain elements in an xml file: #!/usr/bin/env python2.5 import doctest from xml.etree import ElementTree from StringIO import StringIO def parse_xml_etree(sin, xpath): """ Takes as input a stream containing XML and an XPath expression. Applies the XPath expression to the XML and returns a generator yielding the text contents of each element returned. >>> parse_xml_etree( ... StringIO('<test><elem1>one</elem1><elem2>two</elem2></test>'), ... '//elem1').next() 'one' >>> parse_xml_etree( ... StringIO('<test><elem1>one</elem1><elem2>two</elem2></test>'), ... '//elem2').next() 'two' >>> parse_xml_etree( ... StringIO('<test><null>&#0;</null><elem3>three</elem3></test>'), ... '//elem2').next() 'three' """ tree = ElementTree.parse(sin) for element in tree.findall(xpath): yield element.text if __name__ == '__main__': doctest.testmod(verbose=True) The third test fails with the following exception: ExpatError: reference to invalid character number: line 1, column 13 Is the � entity illegal XML? Regardless whether it is or not, the files I want to parse contain it, and I need some way to parse them. Any suggestions for another parser than Expat, or settings for Expat, that would allow me to do that?

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  • Complex sorting on MySQL database

    - by ChrisR
    I'm facing the following situation. We've got an CMS with an entity with translations. These translations are stored in a different table with a one-to-many relationship. For example newsarticles and newsarticle_translations. The amount of available languages is dynamically determined by the same CMS. When entering a new newsarticle the editor is required to enter at least one translation, which one of the available languages he chooses is up to him. In the newsarticle overview in our CMS we would like to show a column with the (translated) article title, but since none of the languages are mandatory (one of them is mandatory but i don't know which one) i don't really know how to construct my mysql query to select a title for each newsarticle, regardless of the entered language. And to make it all a little harder, our manager asked for the possibilty to also be able to sort on title, so fetching the translations in a separate query is ruled out as far as i know. Anyone has an idea on how to solve this in the most efficient way? Here are my table schema's it it might help > desc news; +-----------------+----------------+------+-----+-------------------+----------------+ | Field | Type | Null | Key | Default | Extra | +-----------------+----------------+------+-----+-------------------+----------------+ | id | int(10) | NO | PRI | NULL | auto_increment | | category_id | int(1) | YES | | NULL | | | created | timestamp | NO | | CURRENT_TIMESTAMP | | | user_id | int(10) | YES | | NULL | | +-----------------+----------------+------+-----+-------------------+----------------+ > desc news_translations; +-----------------+------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-----------------+------------------+------+-----+---------+----------------+ | id | int(10) unsigned | NO | PRI | NULL | auto_increment | | enabled | tinyint(1) | NO | | 0 | | | news_id | int(1) unsigned | NO | | NULL | | | title | varchar(255) | NO | | | | | summary | text | YES | | NULL | | | body | text | NO | | NULL | | | language | varchar(2) | NO | | NULL | | +-----------------+------------------+------+-----+---------+----------------+ PS: i've though about subqueries and coalesce() solutions but those seem rather dirty tricks, wondering if something better is know that i'm not thinking of?

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  • iPhone Development - CoreData runtime error

    - by Mustafa
    I'm facing a strange CoreData issue. Here's the log: 2010-04-07 15:59:36.913 MyProject[263:207] <MyEntity: 0x180370> (entity: MyEntity; id: 0x17e890 <x-coredata://0F55C533-41BD-4F09-9CCA-0CB304CAB065/MyEntity/p380> ; data: <fault>) 2010-04-07 15:59:36.918 MyProject[263:207] *** Terminating app due to uncaught exception 'NSObjectInaccessibleException', reason: 'The NSManagedObject with ID:0x17e890 <x-coredata://0F55C533-41BD-4F09-9CCA-0CB304CAB065/MyEntity/p380> has been invalidated.' I have a hierarchy of UITableViewControllers that use NSFetchedResultsController to populate the table, and when a particular row is selected, the detail view is shown. UITableView (MyMainEntity) UITableView (MyEntity) UITableView (MyEntity) detail view Both MyMainEntity UITableView and MyEntity UITableView use NSFetchedResultsController to show the records. Sometimes it crashes when i'm scrolling the tableView, and sometimes it crashes when i try to open the detail view. I can navigate to the MyEntity detail view multiple times before application crashes. What does this error mean? and how can i fix it!?

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  • google app engine atomic section???

    - by bokertov
    hi, Say you retrieve a set of records from the datastore (something like: select * from MyClass where reserved='false'). how do i ensure that another user doesn't set the reserved is still false? I've looked in the Transaction documentation and got shocked from google's solution which is to catch the exception and retry in a loop. Any solution that I'm missing - it's hard to believe that there's no way to have an atomic operation in this environment. (btw - i could use 'syncronize' inside the servlet but i think it's not valid as there's no way to ensure that there's only one instance of the servlet object, isn't it? same applies to static variable solution) Any idea on how to solve??? (here's the google solution: http://code.google.com/appengine/docs/java/datastore/transactions.html#Entity_Groups look at: Key k = KeyFactory.createKey("Employee", "k12345"); Employee e = pm.getObjectById(Employee.class, k); e.counter += 1; pm.makePersistent(e); This requires a transaction because the value may be updated by another user after this code fetches the object, but before it saves the modified object. Without a transaction, the user's request will use the value of counter prior to the other user's update, and the save will overwrite the new value. With a transaction, the application is told about the other user's update. If the entity is updated during the transaction, then the transaction fails with an exception. The application can repeat the transaction to use the new data. THANKS!

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  • Help: List contents of iPhone application bundle subpath??

    - by bluepill
    Hi, I am trying to get a listing of the directories contained within a subpath of my application bundle. I've done some searching and this is what I have come up with - (void) contents { NSArray *contents = [[NSBundle mainBundle] pathsForResourcesOfType:nil inDirectory:@"DataDir"]; if (contents = nil) { NSLog(@"Failed: path doesn't exist or error!"); } else { NSString *bundlePathName = [[NSBundle mainBundle] bundlePath]; NSString *dataPathName = [bundlePathName stringByAppendingPathComponent: @"DataDir"]; NSFileManager *fileManager = [NSFileManager defaultManager]; NSMutableArray *directories = [[NSMutableArray alloc] init]; for (NSString *entityName in contents) { NSString *fullEntityName = [dataPathName stringByAppendingPathComponent:entityName]; NSLog(@"entity = %@", fullEntityName); BOOL isDir = NO; [fileManager fileExistsAtPath:fullEntityName isDirectory:(&isDir)]; if (isDir) { [directories addObject:fullEntityName]; NSLog(@" is a directory"); } else { NSLog(@" is not a directory"); } } NSLog(@"Directories = %@", directories); [directories release]; } } As you can see I am trying to get a listing of directories in the app bundle's DataDir subpath. The problem is that I get no strings in my contents NSArray. note: - I am using the simulator - When I manually look in the .app file I can see DataDir and the contents therein - The contents of DataDir are png files and directories that contain png files - The application logic needs to discover the contents of DataDir at runtime - I have also tried using NSArray *contents = [fileManager contentsOfDirectoryAtPath:DataDirPathName error:nil]; and I still get no entries in my contents array Any suggestions/alternative approaches? Thanks.

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  • Writing to the DataContext

    - by user738383
    I have a function. This function takes an IEnumerable<Customer> (Customer being an entity). What the function needs to do is tell the DataContext (which has a collection of Customers as a property) that its Customers property needs to be overwritten with this passed in IEnumerable<Customer>. I can't use assignment because DomainContext.Customers cannot be assigned to, as it is read only. I guess it's not clear what I'm asking, so I suppose I should say... how do I do that? So we have DataContext.Customers (of type System.Data.Linq.Table) which wants to be replaced with a System.Collections.Generic.IEnumerable. I can't just assign the latter to the former because DataContext's properties are read only. But there must be a way. Edit: here's an image: Further edit: Yes, this image does not feature a collection of the type 'Customer' but rather 'Connection'. It doesn't matter though, they are both created from tables within the linked SQL database. So there is a dc.Connections, a dc.Customers, a dc.Media and so on. Thanks in advance.

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  • What does P mean in Sort(Expression<Func<T, P>> expr, ListSortDirection direction)?

    - by Grasshopper
    I am attempting to use the answer in post: How do you sort an EntitySet<T> to expose an interface so that I can sort an EntitySet with a Binding list. I have created the class below and I get the following compiler error: "The type or namespace 'P' could not be found (are you missing a using directive or assembly reference?). Can someone tell me what the P means and which namespace I need to include to get the method below to compile? I am very new to delegates and lamba expressions. Also, can someone confirm that if I create a BindingList from my EntitySet that any modifications I make to the BindingList will be made to the EntitySet? Basically, I have an EntitySet that I need to sort and make changes to. Then, I will need to persist these changes using the original Entity that the BindingList came from. public class EntitySetBindingWrapper<T> : BindingList<T> { public EntitySetBindingWrapper(BindingList<T> root) : base(root) { } public void Sort(Expression<Func<T, P>> expr, ListSortDirection direction) { if (expr == null) base.RemoveSortCore(); MemberExpression propExpr = expr as MemberExpression; if (propExpr == null) throw new ArgumentException("You must provide a property", "expr"); PropertyDescriptorCollection descriptorCol = TypeDescriptor.GetProperties(typeof(T)); IEnumerable<PropertyDescriptor> descriptors = descriptorCol.Cast<PropertyDescriptor>(); PropertyDescriptor descriptor = descriptors.First(pd => pd.Name == propExpr.Member.Name); base.ApplySortCore(descriptor, direction); } }

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  • HIbernate 3.5.1 - can I just drop in EHCache 2.0.1?

    - by caerphilly
    I'm using Hibernate 3.5.1, which comes with EHCache 1.5 bundled. If I want to use the latest EHCache release (2.0.1), is it just a matter of removing the ehcache-1.5.jar from my project, and replacing with ehcache-core-2.0.1.jar? Any issues to be aware of? Also - is a cache "region" in the Hibernate mapping file that same as a cache "name" in the ehcache configuration xml? What I want to do is define 2 named cache regions - one for read-only reference entities that won't change (lookup lists etc), and one for all other entities. So in ehcache I want to define two elements; <cache name="readonly"> ... </cache> <cache name="mutable"> ... </cache> And then in my Hibernate mapping files, I will specify the cache to be used for each entity: <hibernate-mapping> <class name="lookuplist"> <cache region="readonly" usage="read-only"/> <property> ... </property> </class> </hibernate-mapping> Will that work? Some of the documentation seems to imply that a separate region/cache gets created for each mapped class... Thanks.

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  • LINQ to SQL - Lightweight O/RM?

    - by CoffeeAddict
    I've heard from some that LINQ to SQL is good for lightweight apps. But then I see LINQ to SQL being used for Stackoverflow, and a bunch of other .coms I know (from interviewing with them). Ok, so is this true? for an e-commerce site that's bringing in millions and you're typically only doing basic CRUDs most the time with the exception of an occasional stored proc for something more complex, is LINQ to SQL complete enough and performance-wise good enough or able to be tweaked enough to run happily on an e-commerce site? I've heard that you just need to tweak performance on the DB side when using LINQ to SQL for a better approach. So there are really 2 questions here: 1) Meaning/scope/definition of a "Lightweight" O/RM solution: What the heck does "lightweight" mean when people say LINQ to SQL is a "lightweight O/RM" and is that true??? If this is so lightweight then why do I see a bunch of huge .coms using it? Is it good enough to run major .coms (obviously it looks like it is) and what determines what the context of "lightweight" is...it's such a generic statement. 2) Performance: I'm working on my own .com and researching different O/RMs. I'm not really looking at the Entity Framework (yet), just want to figure out the LINQ to SQL basics here and determine if it will be efficient enough for me. The problem I think is you can't tweak or control the SQL it generates...

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  • issue with vhdl structural coding

    - by user3699982
    The code below is a simple vhdl structural architecture, however, the concurrent assignment to the signal, comb1, is upsetting the simulation with the outputs (tb_lfsr_out) and comb1 becoming undefined. Please, please help, thank you, Louise. library IEEE; use IEEE.STD_LOGIC_1164.all; entity testbench is end testbench; architecture behavioural of testbench is CONSTANT clock_frequency : REAL := 1.0e9; CONSTANT clock_period : REAL := (1.0/clock_frequency)/2.0; signal tb_master_clk, comb1: STD_LOGIC := '0'; signal tb_lfsr_out : std_logic_vector(2 DOWNTO 0) := "111"; component dff port ( q: out STD_LOGIC; d, clk: in STD_LOGIC ); end component; begin -- Clock/Start Conversion Generator tb_master_clk <= (NOT tb_master_clk) AFTER (1 SEC * clock_period); comb1 <= tb_lfsr_out(0) xor tb_lfsr_out(2); dff6: dff port map (tb_lfsr_out(2), tb_lfsr_out(1), tb_master_clk); dff7: dff port map (tb_lfsr_out(1), tb_lfsr_out(0), tb_master_clk); dff8: dff port map (tb_lfsr_out(0), comb1, tb_master_clk); end behavioural;

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  • Can I split a single SQL 2008 DB Table into multiple filegroups, based on a discriminator column?

    - by Pure.Krome
    Hi folks, I've got a SQL Server 2008 R2 database which has a number of tables. Two of these tables contains a lot of large data .. mainly because one of them is VARBINARY(MAX) and the sister table is GEOGRAPHY. (Why two tables? Read Below if you're interested***) The data in these tables are geospatial shapes, such as zipcode boundaries. Now, the first 70K odd rows are for DataType = 1 the rest 5mil rows are for DataType = 2 Now, is it possible to split the table data into two files? so all rows that are for DataType != 2 goes into File_A and DataType = 2 goes into File_B? This way, when I backup the DB, I can skip adding File_B so my download is waaaaay smaller? Is this possible? I guessing you might be thinking - why not keep them as TWO extra tables? Mainly because in the code, the data is conceptually the same .. it's just happens that I want to split the storage of this model data. It really messes up my model if I now how two aggregates in my model, instead of one. ***Entity Framework doesn't like Tables with GEOGRAPHY, so i have to create a new table which transforms the GEOGRAPHY to VARBINARY, and then drop that into EF.

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  • Hibernate saveOrUpdate fails when I execute it on empty table.

    - by Vladimir
    I'm try to insert or update db record with following code: Category category = new Category(); category.setName('catName'); category.setId(1L); categoryDao.saveOrUpdate(category); When there is a category with id=1 already in database everything works. But if there is no record with id=1 I got following exception: org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1: Here is my Category class setters, getters and constructors ommited for clarity: @Entity public class Category { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; private String name; @ManyToOne private Category parent; @OneToMany(fetch = FetchType.LAZY, mappedBy = "parent") private List<Category> categories = new ArrayList<Category>(); } In the console I see this hibernate query: update Category set name=?, parent_id=? where id=? So looks like hibernates tryis to update record instead of inserting new. What am I doing wrong here?

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  • How can I set the tab on a webpage depending on which page you come from in ASP.Net MVC?

    - by uriDium
    I have a rather large entity. It has a parent relationship with many different child tables. Each of the child tables I have represented as a tab (luckily it makes sense and looks nice and makes things easier to navigate). If the users wants to add a new child row, they go the particular tab, and there they see a list of rows which is owned by the parent and they can do the usual CRUD. The CRUD takes them to a new controller and action and passes the ID of the parent to the action. (This is as far as I can tell what I was meant to do, any other ideas??) When they have finsihed they click save and it takes them back to the original page BUT I want it to automatically go to the right tab. How can I do this? I am using Jquery UI tabs, ASP.Net MVC 2.0. One idea I had was to just go back to the bookmark (the href part with the #, for e.g. /Parent/Details/4/#tabname). Apparently JQuery UI tabs can handle this. Or to set the tab name as part of the query string (/Parent/Details/4?tab=name) What is the best practise here?

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  • Service Layer are repeating my Repositories

    - by Felipe
    Hi all, I'm developing an application using asp.net mvc, NHibernate and DDD. I have a service layer that are used by controllers of my application. Everything are using Unity to inject dependencies (ISessionFactory in repositories, repositories in services and services in controllers) and works fine. But, it's very common I need a method in service to get only object in my repository, like this (in service class): public class ProductService { private readonly IUnitOfWork _uow; private readonly IProductRepository _productRepository; public ProductService(IUnitOfWork unitOfWork, IProductRepository productRepository) { this._uow = unitOfWork; this._productRepository = productRepository; } /* this method should be exists in DDD ??? It's very common */ public Domain.Product Get(long key) { return _productRepository.Get(key); } /* other common method... is correct by DDD ? */ public bool Delete(long key) { usign (var tx = _uow.BeginTransaction()) { try { _productRepository.Delete(key); tx.Commit(); return true; } catch { tx.RollBack(); return false; } } } /* ... others methods ... */ } This code is correct by DDD ? For each Service class I have a Repository, and for each service class need I do a method "Get" for an entity ? Thanks guys Cheers

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  • How to configure multiple mappings using FluentHibernate?

    - by chris.baglieri
    First time rocking it with NHibernate/Fluent so apologies in advance if this is a naive question. I have a set of Models I want to map. When I create my session factory I'm trying to do all mappings at once. I am not using auto-mapping (though I may if what I am trying to do ends up being more painful than it ought to be). The problem I am running into is that it seems only the top map is taking. Given the code snippet below and running a unit test that attempts to save 'bar', it fails and checking the logs I see NHibernate is trying to save a bar entity to the foo table. While I suspect it's my mappings it could be something else that I am simply overlooking. Code that creates the session factory (note I've also tried separate calls into .Mappings): Fluently.Configure().Database(MsSqlConfiguration.MsSql2008 .ConnectionString(c => c .Server(@"localhost\SQLEXPRESS") .Database("foo") .Username("foo") .Password("foo"))) .Mappings(m => { m.FluentMappings.AddFromAssemblyOf<FooMap>() .Conventions.Add(FluentNHibernate.Conventions.Helpers .Table.Is(x => "foos")); m.FluentMappings.AddFromAssemblyOf<BarMap>() .Conventions.Add(FluentNHibernate.Conventions.Helpers .Table.Is(x => "bars")); }) .BuildSessionFactory(); Unit test snippet: using (var session = Data.SessionHelper.SessionFactory.OpenSession()) { var bar = new Bar(); session.Save(bar); Assert.NotNull(bar.Id); }

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  • How can I get my business objects layer to use the management layer in their methods?

    - by Tom Pickles
    I have a solution in VS2010 with several projects, each making up a layer within my application. I have business entities which are currently objects with no methods, and I have a management layer which references the business entities layer in it's project. I now think I have designed my application poorly and would like to move methods from helper classes (which are in another layer) into methods I'll create within the business entities themselves. For example I have a VirtualMachine object, which uses a helper class to call a Reboot() method on it which passes the request to the management layer. The static manager class talks to an API that reboots the VM. I want to move the Reboot() method into the VirtualMachine object, but I will need to reference the management layer: public void Reboot() { VMManager.Reboot(this.Name); } So if I add a reference to my management project in my entities project, I get the circular dependency error, which is how it should be. How can I sort this situation out? Do I need to an yet another layer between the entity layer and the management layer? Or, should I just forget it and leave it as it is. The application works ok now, but I am concerned my design isn't particularly OOP centric and I would like to correct this.

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