Search Results

Search found 2536 results on 102 pages for 'entities'.

Page 94/102 | < Previous Page | 90 91 92 93 94 95 96 97 98 99 100 101  | Next Page >

• Linq to sql C# updating reference Tables

  - by Laurence Burke

  ok reclarification I am adding a new address and I know the structure as AddressID = PK and all other entities are non nullable. Now on insert of a new row the addrID Pk is autogened and I am wondering if I would have to get that to create a new row in the referencing table or does that automatically get generated also. also I want to be able to repopulate the dropdownlist that lists the current employee's addresses with the newly created address. static uint _curEmpID; protected void btnAdd_Click(object sender, EventArgs e) { if (txtZip.Text != "" && txtAdd1.Text != "" && txtCity.Text != "") { TestDataClassDataContext dc = new TestDataClassDataContext(); Address addr = new Address() { AddressLine1 = txtAdd1.Text, AddressLine2 = txtAdd2.Text, City = txtCity.Text, PostalCode = txtZip.Text, StateProvinceID = Convert.ToInt32(ddlState.SelectedValue) }; dc.Addresses.InsertOnSubmit(addr); lblSuccess.Visible = true; lblErrMsg.Visible = false; dc.SubmitChanges(); // // TODO: add reference from new address to CurEmp Table // SetAddrList(); } else { lblErrMsg.Text = "Invalid Input"; lblErrMsg.Visible = true; } } protected void ddlAddList_SelectedIndexChanged(object sender, EventArgs e) { lblErrMsg.Visible = false; lblSuccess.Visible = false; TestDataClassDataContext dc = new TestDataClassDataContext(); dc.ObjectTrackingEnabled = false; if (ddlAddList.SelectedValue != "-1") { var addr = (from a in dc.Addresses where a.AddressID == Convert.ToInt32(ddlAddList.SelectedValue) select a).FirstOrDefault(); txtAdd1.Text = addr.AddressLine1; txtAdd2.Text = addr.AddressLine2; txtCity.Text = addr.City; txtZip.Text = addr.PostalCode; ddlState.SelectedValue = addr.StateProvinceID.ToString(); btnSubmit.Visible = true; btnAdd.Visible = false; } else { txtAdd1.Text = ""; txtAdd2.Text = ""; txtCity.Text = ""; txtZip.Text = ""; btnAdd.Visible = true; btnSubmit.Visible = false; } } protected void SetAddrList() { TestDataClassDataContext dc = new TestDataClassDataContext(); dc.ObjectTrackingEnabled = false; var addList = from addr in dc.Addresses from eaddr in dc.EmployeeAddresses where eaddr.EmployeeID == _curEmpID && addr.AddressID == eaddr.AddressID select new { AddValue = addr.AddressID, AddText = addr.AddressID, }; ddlAddList.DataSource = addList; ddlAddList.DataValueField = "AddValue"; ddlAddList.DataTextField = "AddText"; ddlAddList.DataBind(); ddlAddList.Items.Add(new ListItem("<Add Address>", "-1")); } OK I am hoping that I did not include too much code. I would really appreciate any other comments about I could otherwise improve this code in any other ways also.

  Read the article

• Adding rows with linq trouble with reference table

  - by Laurence Burke

  I am adding a new address and I know the structure as AddressID = PK and all other entities are non nullable. Now on insert of a new row the addrID Pk is autogened and I am wondering if I would have to get that to create a new row in the referencing table EmployeeAddress or does that automatically get generated also. also I want to be able to repopulate the dropdownlist that lists the current employee's addresses with the newly created address. static uint _curEmpID; protected void btnAdd_Click(object sender, EventArgs e) { if (txtZip.Text != "" && txtAdd1.Text != "" && txtCity.Text != "") { TestDataClassDataContext dc = new TestDataClassDataContext(); Address addr = new Address() { AddressLine1 = txtAdd1.Text, AddressLine2 = txtAdd2.Text, City = txtCity.Text, PostalCode = txtZip.Text, StateProvinceID = Convert.ToInt32(ddlState.SelectedValue) }; dc.Addresses.InsertOnSubmit(addr); lblSuccess.Visible = true; lblErrMsg.Visible = false; dc.SubmitChanges(); // // TODO: insert new row in EmployeeAddress to reference CurEmp to newly created address // SetAddrList(); } else { lblErrMsg.Text = "Invalid Input"; lblErrMsg.Visible = true; } } protected void ddlAddList_SelectedIndexChanged(object sender, EventArgs e) { lblErrMsg.Visible = false; lblSuccess.Visible = false; TestDataClassDataContext dc = new TestDataClassDataContext(); dc.ObjectTrackingEnabled = false; if (ddlAddList.SelectedValue != "-1") { var addr = (from a in dc.Addresses where a.AddressID == Convert.ToInt32(ddlAddList.SelectedValue) select a).FirstOrDefault(); txtAdd1.Text = addr.AddressLine1; txtAdd2.Text = addr.AddressLine2; txtCity.Text = addr.City; txtZip.Text = addr.PostalCode; ddlState.SelectedValue = addr.StateProvinceID.ToString(); btnSubmit.Visible = true; btnAdd.Visible = false; } else { txtAdd1.Text = ""; txtAdd2.Text = ""; txtCity.Text = ""; txtZip.Text = ""; btnAdd.Visible = true; btnSubmit.Visible = false; } } protected void SetAddrList() { TestDataClassDataContext dc = new TestDataClassDataContext(); dc.ObjectTrackingEnabled = false; var addList = from addr in dc.Addresses from eaddr in dc.EmployeeAddresses where eaddr.EmployeeID == _curEmpID && addr.AddressID == eaddr.AddressID select new { AddValue = addr.AddressID, AddText = addr.AddressID, }; ddlAddList.DataSource = addList; ddlAddList.DataValueField = "AddValue"; ddlAddList.DataTextField = "AddText"; ddlAddList.DataBind(); ddlAddList.Items.Add(new ListItem("<Add Address>", "-1")); } OK I am hoping that I did not include too much code. I would really appreciate any other comments about I could otherwise improve this code in any other ways also.

  Read the article

• How do I change a child's parent in NHibernate when cascade is delete-all-orphan?

  - by Daniel T.

  I have two entities in a bi-directional one-to-many relationship: public class Storage { public IList<Box> Boxes { get; set; } } public class Box { public Storage CurrentStorage { get; set; } } And the mapping: <class name="Storage"> <bag name="Boxes" cascade="all-delete-orphan" inverse="true"> <key column="Storage_Id" /> <one-to-many class="Box" /> </bag> </class> <class name="Box"> <many-to-one name="CurrentStorage" column="Storage_Id" /> </class> A Storage can have many Boxes, but a Box can only belong to one Storage. I have them mapped so that the one-to-many has a cascade of all-delete-orphan. My problem arises when I try to change a Box's Storage. Assuming I already ran this code: var storage1 = new Storage(); var storage2 = new Storage(); storage1.Boxes.Add(new Box()); Session.Create(storage1); Session.Create(storage2); The following code will give me an exception: // get the first and only box in the DB var existingBox = Database.GetBox().First(); // remove the box from storage1 existingBox.CurrentStorage.Boxes.Remove(existingBox); // add the box to storage2 after it's been removed from storage1 var storage2 = Database.GetStorage().Second(); storage2.Boxes.Add(existingBox); Session.Flush(); // commit changes to DB I get the following exception: NHibernate.ObjectDeletedException : deleted object would be re-saved by cascade (remove deleted object from associations) This exception occurs because I have the cascade set to all-delete-orphan. The first Storage detected that I removed the Box from its collection and marks it for deletion. However, when I added it to the second Storage (in the same session), it attempts to save the box again and the ObjectDeletedException is thrown. My question is, how do I get the Box to change its parent Storage without encountering this exception? I know one possible solution is to change the cascade to just all, but then I lose the ability to have NHibernate automatically delete a Box by simply removing it from a Storage and not re-associating it with another one. Or is this the only way to do it and I have to manually call Session.Delete on the box in order to remove it?

  Read the article

• Under what circumstances would a LINQ-to-SQL Entity "lose" a changed field?

  - by John Rudy

  I'm going nuts over what should be a very simple situation. In an ASP.NET MVC 2 app (not that I think this matters), I have an edit action which takes a very small entity and makes a few changes. The key portion (outside of error handling/security) looks like this: Todo t = Repository.GetTodoByID(todoID); UpdateModel(t); Repository.Save(); Todo is the very simple, small entity with the following fields: ID (primary key), FolderID (foreign key), PercentComplete, TodoText, IsDeleted and SaleEffortID (foreign key). Each of these obviously corresponds to a field in the database. When UpdateModel(t) is called, t does get correctly updated for all fields which have changed. When Repository.Save() is called, by the time the SQL is written out, FolderID reverts back to its original value. The complete code to Repository.Save(): public void Save() { myDataContext.SubmitChanges(); } myDataContext is an instance of the DataContext class created by the LINQ-to-SQL designer. Nothing custom has been done to this aside from adding some common interfaces to some of the entities. I've validated that the FolderID is getting lost before the call to Repository.Save() by logging out the generated SQL: UPDATE [Todo].[TD_TODO] SET [TD_PercentComplete] = @p4, [TD_TodoText] = @p5, [TD_IsDeleted] = @p6 WHERE ([TD_ID] = @p0) AND ([TD_TDF_ID] = @p1) AND /* Folder ID */ ([TD_PercentComplete] = @p2) AND ([TD_TodoText] = @p3) AND (NOT ([TD_IsDeleted] = 1)) AND ([TD_SE_ID] IS NULL) /* SaleEffort ID */ -- @p0: Input BigInt (Size = -1; Prec = 0; Scale = 0) [5] -- @p1: Input BigInt (Size = -1; Prec = 0; Scale = 0) [1] /* this SHOULD be 4 and in the update list */ -- @p2: Input TinyInt (Size = -1; Prec = 0; Scale = 0) [90] -- @p3: Input NVarChar (Size = 4000; Prec = 0; Scale = 0) [changing text] -- @p4: Input TinyInt (Size = -1; Prec = 0; Scale = 0) [0] -- @p5: Input NVarChar (Size = 4000; Prec = 0; Scale = 0) [changing text foo] -- @p6: Input Bit (Size = -1; Prec = 0; Scale = 0) [True] -- Context: SqlProvider(Sql2005) Model: AttributedMetaModel Build: 4.0.30319.1 So somewhere between UpdateModel(t) (where I've validated in the debugger that FolderID updated) and the output of this SQL, the FolderID reverts. The other fields all save. (Well, OK, I haven't validated SaleEffortID yet, because that subsystem isn't really ready yet, but everything else saves.) I've exhausted my own means of research on this: Does anyone know of conditions which would cause a partial entity reset (EG, something to do with long foreign keys?), and/or how to work around this?

  Read the article

• IQueryable and lazy loading

  - by Nelson

  I'm having a hard time determining the best way to handle this... With Entity Framework (and L2S), LINQ queries return IQueryable. I have read various opinions on whether the DAL/BLL should return IQueryable, IEnumerable or IList. Assuming we go with IList, then the query is run immediately and that control is not passed on to the next layer. This makes it easier to unit test, etc. You lose the ability to refine the query at higher levels, but you could simply create another method that allows you to refine the query and still return IList. And there are many more pros/cons. So far so good. Now comes Entity Framework and lazy loading. I am using POCO objects with proxies in .NET 4/VS 2010. In the presentation layer I do: foreach (Order order in bll.GetOrders()) { foreach (OrderLine orderLine in order.OrderLines) { // Do something } } In this case, GetOrders() returns IList so it executes immediately before returning to the PL. But in the next foreach, you have lazy loading which executes multiple SQL queries as it gets all the OrderLines. So basically, the PL is running SQL queries "on demand" in the wrong layer. Is there any sensible way to avoid this? I could turn lazy loading off, but then what's the point of having this "feature" that everyone was complaining EF1 didn't have? And I'll admit it is very useful in many scenarios. So I see several options: Somehow remove all associations in the entities and add methods to return them. This goes against the default EF behavior/code generation and makes it harder to do some composite (multiple entity) LINQ queries. It seems like a step backwards. I vote no. If we have lazy loading anyway which makes it hard to unit test, then go all the way and return IQueryable. You'll have more control farther up the layers. I still don't think this is a good option because IQueryable ties you to L2S, L2E, or your own full implementation of IQueryable. Lazy loading may run queries "on demand", but doesn't tie you to any specific interface. I vote no. Turn off lazy loading. You'll have to handle your associations manually. This could be with eager loading's .Include(). I vote yes in some specific cases. Keep IList and lazy loading. I vote yes in many cases, only due to the troubles with the others. Any other options or suggestions? I haven't found an option that really convinces me.

  Read the article

• How can i convert this to a factory/abstract factory?

  - by Amitd

  I'm using MigraDoc to create a pdf document. I have business entities similar to the those used in MigraDoc. public class Page{ public List<PageContent> Content { get; set; } } public abstract class PageContent { public int Width { get; set; } public int Height { get; set; } public Margin Margin { get; set; } } public class Paragraph : PageContent{ public string Text { get; set; } } public class Table : PageContent{ public int Rows { get; set; } public int Columns { get; set; } //.... more } In my business logic, there are rendering classes for each type public interface IPdfRenderer<T> { T Render(MigraDoc.DocumentObjectModel.Section s); } class ParagraphRenderer : IPdfRenderer<MigraDoc.DocumentObjectModel.Paragraph> { BusinessEntities.PDF.Paragraph paragraph; public ParagraphRenderer(BusinessEntities.PDF.Paragraph p) { paragraph = p; } public MigraDoc.DocumentObjectModel.Paragraph Render(MigraDoc.DocumentObjectModel.Section s) { var paragraph = s.AddParagraph(); // add text from paragraph etc return paragraph; } } public class TableRenderer : IPdfRenderer<MigraDoc.DocumentObjectModel.Tables.Table> { BusinessEntities.PDF.Table table; public TableRenderer(BusinessEntities.PDF.Table t) { table =t; } public MigraDoc.DocumentObjectModel.Tables.Table Render(Section obj) { var table = obj.AddTable(); //fill table based on table } } I want to create a PDF page as : var document = new Document(); var section = document.AddSection();// section is a page in pdf var page = GetPage(1); // get a page from business classes foreach (var content in page.Content) { //var renderer = createRenderer(content); // // get Renderer based on Business type ?? // renderer.Render(section) } For createRenderer() i can use switch case/dictionary and return type. How can i get/create the renderer generically based on type ? How can I use factory or abstract factory here? Or which design pattern better suits this problem?

  Read the article

• Repeating fields in similar database tables

  - by user1738833

  I have been tasked with working on a database that I have never seen before and I'm looking at the DB structure. Some of the central and most heavily queried and joined tables look like virtual duplicates of each other. Here's a massively simplified representation of the situation, with business-sensitive information changed, listing hypothetical table names and fields: TopLevelGroup: PK_TLGroupId, DisplaysXOnBill, DisplaysYOnBill, IsInvoicedForJ, IsInvoicedForK SubGroup: PK_SubGroupId, FK_ParentTopLevelGroupId, DisplaysXOnBill, DisplaysYOnBill, IsInvoicedForJ, IsInvoicedForK SubSubGroup: PK_SubSUbGroupId, FK_ParentSubGroupId, DisplaysXOnBill, DisplaysYOnBill, IsInvoicedForJ, IsInvoicedForK I haven't listed the types of the fields as I don't think it's particularly important to the situation. In addition, it's worth saying that rather than four repeated fields as in the example above, I'm looking at 86 repeated fields. For the most part, those fields genuinely do represent "facts" about the primary table entity, so it's not automatically wrong for that reason. In addition, the "groups" represented here have a property inheritance relationship. If DisplaysXOnBill is NULL in the SubSubGroup, it takes the value of DisplaysXOnBillfrom it's parent, the SubGroup, and so-on up to the TopLevelGroup. Further, the requirements will never require that the model extends beyond three levels, so there is no need for flexibility in that area. Is there a design smell from several tables which describe very similar entities having almost identical fields? If so, what might be a better design of the example above? I'm using the phrase "design smell" to indicate a possible problem. Of course, in any given situation, a particular design might well be the best solution. I'm looking for a more general answer - wondering what might be wrong with this design and what might be the better design were that the case. Possibly related, but not primary questions: Is this database schema in a reasonably normal form (e.g. to 3NF), insofar as can be told from the information I've provided. I can't see a problem with the requirements of 2NF and 3NF, except in their inheriting the requirements of 1NF. Is 1NF satisfied though? Are repeating groups allowed in different tables? Is there a best-practice method for implementing the inheritance relationship in a database as I require? The method above feels clunky to me because any query on the SubSubGroup necessarily needs to join onto the SubGroup and the TopLevelGroup tables to collect inherited facts, which can make even trivial joins requiring facts from the SubSubGroup table rather long-winded. There are, of course, political considerations to making a relatively large change like this. For the purpose of this question, I'm happy to ignore that fact in the interests of keeping the answers ring-fenced to the technical problem.

  Read the article

• Transaction on Entity FrameWork Refactoring and best performance how can i?

  - by programmerist

  i try to use transaction in Entity FrameWork. i have 3 tables Personel, Prim, Finans. in Prim table you look SatisTutari (int) if i add data in SatisTutari.Text instead of int value adding float value. Trannsaction must be run! Everything is ok but how can i refactoring or give best performance or best writing Transaction coding! i have 3 table so i have 3 entities: CREATE TABLE Personel (PersonelID integer PRIMARY KEY identity not null, Ad varchar(30), Soyad varchar(30), Meslek varchar(100), DogumTarihi datetime, DogumYeri nvarchar(100), PirimToplami float); Go create TABLE Prim (PrimID integer PRIMARY KEY identity not null, PersonelID integer Foreign KEY references Personel(PersonelID), SatisTutari int, Prim float, SatisTarihi Datetime); Go CREATE TABLE Finans (ID integer PRIMARY KEY identity not null, Tutar float); Personel, Prim,Finans my tables. if you look Prim table you can see Prim value float value if i write a textbox not float value my transaction must run. protected void btnSave_Click(object sender, EventArgs e) { using (TestEntities testCtx = new TestEntities()) { using (TransactionScope scope = new TransactionScope()) { Personel personel = new Personel(); Prim prim = new Prim(); Finans finans = new Finans(); //-----------------------------------------------------------------------Step 1 personel.Ad = txtName.Text; personel.Soyad = txtSurName.Text; personel.Meslek = txtMeslek.Text; personel.DogumTarihi = DateTime.Parse(txtSatisTarihi.Text); personel.DogumYeri = txtDogumYeri.Text; personel.PirimToplami = float.Parse(txtPrimToplami.Text); testCtx.AddToPersonel(personel); testCtx.SaveChanges(); //----------------------------------------------------------------------- step 2 prim.PersonelID = personel.PersonelID; prim.SatisTutari = int.Parse(txtSatisTutari.Text); prim.SatisTarihi = DateTime.Parse(txtSatisTarihi.Text); prim.Prim1 = double.Parse(txtPrim.Text); finans.Tutar = prim.SatisTutari * prim.Prim1; testCtx.AddToPrim(prim); testCtx.SaveChanges(); //----------------------------------------------------------------------- step 3 lblTutar.Text = finans.Tutar.Value.ToString(); testCtx.AddToFinans(finans); testCtx.SaveChanges(); scope.Complete(); } } How can i rearrange codes. i need best practice refactoring and best solution for reading easly and performance!!!

  Read the article

• With NHibernate, how can I create an INHibernateProxy?

  - by Eric

  After lots of reading about serialization, I've decided to try to create DTOs. After more reading, I decided to use AutoMapper. What I would like to do is transform the parent (easy enough) and transform the entity properties if they've been initialized, which I've done with ValueResolvers like below (I may try to make it generic once I get it fully working). This part works. public class OrderItemResolver : ValueResolver<Order, OrderItem> { protected override OrderItem ResolveCore(Order source) { // could also use NHibernateUtil.IsInitialized(source.OrderItem) if (source.OrderItem is NHibernate.Proxy.INHibernateProxy) return null; else return source.OrderItem; } } } When I transform the DTO back to an entity, for the entities that weren't initialized, I want to create a proxy so that if the entity wants to access it, it can. However, I can't figure out how to create a proxy. I'm using Castle if that's relevant. I've tried a bunch of things with no luck. The below code is a mess, mainly because I've been trying things at random without knowing what I should be doing. Anybody have any suggestions? public class OrderItemDTOResolver : ValueResolver<OrderDTO, OrderItem> { protected override OrderItem ResolveCore(OrderDTO source) { if (source.OrderItem == null) { //OrderItem OrderItem = new ProxyGenerator().CreateClassProxy<OrderItem>(); // Castle.Core.Interceptor. //OrderItem OrderItem = new ProxyGenerator().CreateClassProxy<OrderItem>(); //OrderItem.Id = source.OrderItemId; //OrderItem OrderItem = new OrderItem(); //var proxy = new OrderItem() as INHibernateProxy; //var proxy = OrderItem as INHibernateProxy; //return (OrderItem)proxy.HibernateLazyInitializer //ILazyInitializer proxy = new LazyInitializer("OrderItem", OrderItem, source.OrderItemId, null, null, null, null); //return (OrderItem)proxy; //return (OrderItem)proxy.HibernateLazyInitializer.GetImplementation(); //return OrderItem; IProxyTargetAccessor proxy = new Castle.Core.Interceptor. var initializer = new LazyInitializer("OrderItem", typeof(OrderItem), source.OrderItemId, null, null, null, null); //var proxyFactory = new SerializableProxyFactory{Interfaces = Interfaces, TargetSource = initializer, ProxyTargetType = IsClassProxy}; //proxyFactory.AddAdvice(initializer); //object proxyInstance = proxyFactory.GetProxy(); //return (INHibernateProxy) proxyInstance; return null; //OrderItem.Id = source.OrderItemId; //return OrderItem; } else return OrderItemDTO.Unmap(source.OrderItem); } } Thanks, Eric

  Read the article

• Error: java.lang.ClassCastException

  - by theJava

  Updating the entire post. public Login authenticate(Login login) { String query = "SELECT email, id FROM Login WHERE email=? AND password=?"; Object[] parameters = { login.getEmail(), login.getPassword() }; List resultsList = getHibernateTemplate().find(query,parameters); if ( resultsList.size() == 1 ) { results = (Login)resultsList.get(0); System.out.println(results); } else { System.out.println("Error dude.... "); // error no entity or mutiple entities } return results; } I now return Login Objects. private void checkLogin() { form.commit(); Login newUser = new Login(); newUser = ilogin.authenticate(loginbean); System.out.println("Its Null Value" + newUser); if (newUser == null) { getWindow().showNotification("Login failed", LOGIN_ERROR_MSG, Notification.TYPE_WARNING_MESSAGE); } else { System.out.println(newUser); getApplication().setUser(newUser); } } When there is no matching email, i get there is no such user and also this statement does get printed out. System.out.println("Its Null Value" + newUser); But when there is a email and password matching. I get weird error. Caused by: java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to com.intermedix.domain.Login at com.intermedix.services.LoginService.authenticate(LoginService.java:30) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:301) at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:182) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:149) at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:106) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171) at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204) at $Proxy32.authenticate(Unknown Source) at com.intermedix.ui.LoginDailog.checkLogin(LoginDailog.java:106) at com.intermedix.ui.LoginDailog.access$0(LoginDailog.java:102) at com.intermedix.ui.LoginDailog$1.buttonClick(LoginDailog.java:52) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at com.vaadin.event.ListenerMethod.receiveEvent(ListenerMethod.java:487) ... 26 more

  Read the article

• How do I update with a newly-created detached entity using NHibernate?

  - by Daniel T.

  Explanation: Let's say I have an object graph that's nested several levels deep and each entity has a bi-directional relationship with each other. A -> B -> C -> D -> E Or in other words, A has a collection of B and B has a reference back to A, and B has a collection of C and C has a reference back to B, etc... Now let's say I want to edit some data for an instance ofC. In Winforms, I would use something like this: var instanceOfC; using (var session = SessionFactory.OpenSession()) { // get the instance of C with Id = 3 instanceOfC = session.Linq<C>().Where(x => x.Id == 3); } SendToUIAndLetUserUpdateData(instanceOfC); using (var session = SessionFactory.OpenSession()) { // re-attach the detached entity and update it session.Update(instanceOfC); } In plain English, we grab a persistent instance out of the database, detach it, give it to the UI layer for editing, then re-attach it and save it back to the database. Problem: This works fine for Winform applications because we're using the same entity all throughout, the only difference being that it goes from persistent to detached to persistent again. The problem occurs when I'm using a web service and a browser, sending over JSON data. In this case, the data that comes back is no longer a detached entity, but rather a transient one that just happens to have the same ID as the persistent one. If I use this entity to update, it will wipe out the relationship to B and D unless I sent the entire object graph over to the UI and got it back in one piece. Question: My question is, how do I serialize detached entities over the web, receive them back, and save them, while preserving any relationships that I didn't explicitly change? I know about ISession.SaveOrUpdateCopy and ISession.Merge() (they seem to do the same thing?), but this will still wipe out the relationships if I don't explicitly set them. I could copy the fields from the transient entity to the persistent entity one by one, but this doesn't work too well when it comes to relationships and I'd have to handle version comparisons manually.

  Read the article

• Problem while adding new Object to CoreData App

  - by elementsense

  Hi Another Day, another CoreData problem,...but hopefully the last one now. Ok here is a copy of what I have : I have a List of Hotel Guests that stay in one Room and have Preferences. Once ready the user should select a guest and see the data and should also be able to add new guest, select the room (maintained also by application) and select their preferences (where the user can also add new preferences). The guest can have no or many preferences. So here is what I have so far. I created 3 Entities : - Rooms with roomnumber - Preferences with name - GuestInfo with name - with these Relationships room (Destination Rooms) and prefs (Destination Preferences with "To-Many Relationship") The prefs is a NSSet when you create a Managed Object Class. Now I created a UITableViewController to display all the data. I also have an edit and add mode. When I add a new Guest and just fill out the name, everything works fine. But when I want to add the prefs or the room number I get this error : Illegal attempt to establish a relationship 'room' between objects in different contexts Now, what confuses me is that when I add a guest and enter just the name, save it, go back and edit it and select the prefs and room number it works ? I have this line in both ViewControllers to select the room or prefs : [editedObject setValue:selectedRoom forKey:editedFieldKey]; with this .h : NSManagedObject *editedObject; NSString *editedFieldKey; NSString *editedFieldName; Again, it works on the editing mode but not when I want to add a fresh object. And to be sure, this is what I do for adding an new Guest : - (IBAction)addNewItem { AddViewController *addViewController = [[AddViewController alloc] initWithStyle:UITableViewStyleGrouped]; addViewController.delegate = self; addViewController.context = _context; // Create a new managed object context for the new book -- set its persistent store coordinator to the same as that from the fetched results controller's context. NSManagedObjectContext *addingContext = [[NSManagedObjectContext alloc] init]; self.addingManagedObjectContext = addingContext; [addingContext release]; [addingManagedObjectContext setPersistentStoreCoordinator:[[_fetchedResultsController managedObjectContext] persistentStoreCoordinator]]; GuestInfo *info = (GuestInfo *)[NSEntityDescription insertNewObjectForEntityForName:@"GuestInfo" inManagedObjectContext:addingContext]; addViewController.info = info; UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:addViewController]; [self.navigationController presentModalViewController:navController animated:YES]; [addViewController release]; [navController release]; } Anything I have to do to initialize the Room or Prefs ? Hope someone can help me out. Thanks

  Read the article

• PHP 'instanceof' failing with class constant

  - by Nathan Loding

  I'm working on a framework that I'm trying to type as strongly as I possibly can. (I'm working within PHP and taking some of the ideas that I like from C# and trying to utilize them within this framework.) I'm creating a Collection class that is a collection of domain entities/objects. It's kinda modeled after the List<T> object in .Net. I've run into an obstacle that is preventing me from typing this class. If I have a UserCollection, it should only allow User objects into it. If I have a PostCollection, it should only allow Post objects. All Collections in this framework need to have certain basic functions, such as add, remove, iterate. I created an interface, but found that I couldn't do the following: interface ICollection { public function add($obj) } class PostCollection implements ICollection { public function add(Post $obj) {} } This broke it's compliance with the interface. But I can't have the interface strongly typed because then all Collections are of the same type. So I attempted the following: interface ICollection { public function add($obj) } abstract class Collection implements ICollection { const type = 'null'; } class PostCollection { const type = 'Post'; public function add($obj) { if(!($obj instanceof self::type)) { throw new UhOhException(); } } } When I attempt to run this code, I get syntax error, unexpected T_STRING, expecting T_VARIABLE or '$' on the instanceof statement. A little research into the issue and it looks like the root of the cause is that $obj instanceof self is valid to test against the class. It appears that PHP doesn't process the entire self::type constant statement in the expression. Adding parentheses around the self::type variable threw an error regarding an unexpected '('. An obvious workaround is to not make the type variable a constant. The expression $obj instanceof $this->type works just fine (if $type is declared as a variable, of course). I'm hoping that there's a way to avoid that, as I'd like to define the value as a constant to avoid any possible change in the variable later. Any thoughts on how I can achieve this, or have I take PHP to it's limit in this regard? Is there a way of "escaping" or encapsulating self::this so that PHP won't die when processing it?

  Read the article

• how to delete fk children in nhibernate

  - by frosty

  I would like to delete the ICollection PriceBreaks from Product. I'm using the following method. However they dont seem to delete. What am i missing. When i step thru. i notice that "product.PriceBreaks.Clear();" doesn't actually clear the items. Do i need to flush or something? public void RemovePriceBreak(int productId) { using (ISession session = EStore.Domain.Helpers.NHibernateHelper.OpenSession()) using (ITransaction transaction = session.BeginTransaction()) { var product = session.Get<Product>(productId); product.PriceBreaks.Clear(); session.SaveOrUpdate(product); transaction.Commit(); } } Here are my hbm files <class name="Product" table="Products"> <id name="Id" type="Int32" column="Id" unsaved-value="0"> <generator class="identity"/> </id> <property name="CompanyId" column="CompanyId" type="Int32" not-null="true" /> <property name="Name" column="Name"/> <set name="PriceBreaks" table="PriceBreaks" generic="true" cascade="all-delete-orphan" inverse="true" > <key column="ProductId" /> <one-to-many class="EStore.Domain.Model.PriceBreak, EStore.Domain" /> </set> </class> <class name="PriceBreak" table="PriceBreaks"> <id name="Id" type="Int32" column="Id" unsaved-value="0"> <generator class="identity"/> </id> <many-to-one name="Product" column="ProductId" not-null="true" cascade="all" class="EStore.Domain.Model.Product, EStore.Domain" /> </class> My Entities public class Product { public virtual int Id { get; set; } public virtual ICollection<PriceBreak> PriceBreaks { get; set; } public virtual void AddPriceBreak(PriceBreak priceBreak) { priceBreak.Product = this; PriceBreaks.Add(priceBreak); } } public class PriceBreak { public virtual int Id { get; set; } public virtual Product Product { get; set; } }

  Read the article

• CoreData : App crashes when deleting last instance created

  - by Leo

  Hello, I have a 2 tabs application. In the first one, I'm creating objects of the "Sample" and "SampleList" entities. Each sampleList contains an ID and a set of samples. Each sample contains a date and temperature property. In the second tab, I'm displaying my data in a tableView. I implemented the - (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath method in order to delete SampleLists. In my xcdatamodel the delete rule for my relationship between SampleList and Sample is Cascade. My problem is that when I try to delete SampleList I just created, the app crashes and I receive a EXC_BAD_ACCESS signal. If I restart it, then I'm able to delete "old" sampleList without any problems. Earlier, I had the following problem : I couldn't display the the sampleLists I created since I launched the app, because it crashed too. I received also the EXC_BAD_ACCESS signal. Actually, it seemed that the date of the last sample created of the set was nil. If I am not releasing the NSDate I'm using to set the sample's date, I don't have this problem anymore... If anyone could help me to find out what could cause my troubles it would be great !! Here is the method I'm using to create new instances : SampleList *newSampleList = (SampleList *)[NSEntityDescription insertNewObjectForEntityForName:@"SampleList" inManagedObjectContext:managedObjectContext]; [newSampleList setPatchID:patchID]; NSMutableSet *newSampleSet = [[NSMutableSet alloc] init]; NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar]; for (int i = 0; i < [byteArray count]; i=i+4, sampleCount++) { NSDateComponents *comps = [[NSDateComponents alloc] init]; [comps setYear:year]; [comps setMonth:month]; [comps setDay:day]; [comps setHour:hours]; [comps setMinute:minutes]; NSDate *sampleDate = [gregorian dateFromComponents:comps]; Sample *newSample = (Sample *)[NSEntityDescription insertNewObjectForEntityForName:@"Sample" inManagedObjectContext:managedObjectContext]; [newSample setSampleDate:sampleDate]; [newSample setSampleTemperature:[NSNumber numberWithInt:temperature]]; [newSampleSet addObject:newSample]; [comps release]; //[sampleDate release]; } [newSampleList setSampleSet:newSampleSet]; // [newSampleSet release]; NSError *error; if (![managedObjectContext save:&error]) { NSLog(@"Could not Save the context !!"); } [gregorian release];

  Read the article

• How can I edit an entity in MVC4 with EF5 which has a unique constraint?

  - by Yoeri

  [HttpPost] public ActionResult Edit(Car car) { if (ModelState.IsValid) { db.Entry(car).State = EntityState.Modified; db.SaveChanges(); return RedirectToAction("Index"); } return View(car); } This is a controller method scaffolded by MCV 4 My "car" entity has a unique field: LicensePlate. I have custom validation on my Entity: Validation: public partial class Car { partial void ValidateObject(ref List<ValidationResult> validationResults) { using (var db = new GarageIncEntities()) { if (db.Cars.Any(c => c.LicensePlate.Equals(this.LicensePlate))) { validationResults.Add( new ValidationResult("This licenseplate already exists.", new string[]{"LicensePlate"})); } } } } should it be usefull, my car entity: public partial class Car:IValidatableObject { public int Id { get; set; } public string Color { get; set; } public int Weight { get; set; } public decimal Price { get; set; } public string LicensePlate { get; set; } public System.DateTime DateOfSale { get; set; } public int Type_Id { get; set; } public int Fuel_Id { get; set; } public virtual CarType Type { get; set; } public virtual Fuel Fuel { get; set; } public IEnumerable<ValidationResult> Validate(ValidationContext validationContext) { var result = new List<ValidationResult>(); ValidateObject(ref result); return result; } partial void ValidateObject(ref List<ValidationResult> validationResults); } QUESTION: Everytime I edit a car, it raises an error: Validation failed for one or more entities. See 'EntityValidationErrors' property for more details. The error is the one raised by my validation, saying it can't edit because there is already a car with that license plate. If anyone could point me in the right direction to fix this, that would be great! I searched but couldn't find anything, so even related posts are welcome!

  Read the article

• NSSortDescriptor for NSFetchRequestController causes crash when value of sorted attribute is changed

  - by AJ

  I have an Core Data Entity with a number of attributes, which include amount(float), categoryTotal(float) and category(string) The initial ViewController uses a FethchedResultsController to retrieve the entities, and sorts them based on the category and then the categoryTotal. No problems so far. NSManagedObjectContext *moc = [self managedObjectContext]; NSEntityDescription *entityDescription = [NSEntityDescription entityForName:@"Transaction" inManagedObjectContext:moc]; NSFetchRequest *request = [[[NSFetchRequest alloc] init] autorelease]; [request setEntity:entityDescription]; NSPredicate *predicate = [NSPredicate predicateWithFormat:@"(dateStamp >= %@) AND (dateStamp =< %@)", startDate, endDate]; [request setPredicate:predicate]; NSSortDescriptor *sortByCategory = [[NSSortDescriptor alloc] initWithKey:@"category" ascending:sortOrder]; NSSortDescriptor *sortByTotals = [[NSSortDescriptor alloc] initWithKey:@"categoryTotal" ascending:sortOrder]; NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortByTotals, sortByCategory, nil]; [request setSortDescriptors:sortDescriptors]; NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:request managedObjectContext:managedObjectContext sectionNameKeyPath:@"category" cacheName:nil]; aFetchedResultsController.delegate = self; self.fetchedResultsController = aFetchedResultsController; On selecting a row (tableView:didSelectRowAtIndexPath), another view controller is loaded that allows editing of the amount field for the selected entity. Before returning to the first view, categoryTotal is updated by the new ‘amount’. The problem comes when returning to the first view controller, the app bombs with *Serious application error. Exception was caught during Core Data change processing: Invalid update: invalid number of rows in section 0. The number of rows contained in an existing section after the update (1) must be equal to the number of rows contained in that section before the update (1), plus or minus the number of rows inserted or deleted from that section (0 inserted, 1 deleted). with userInfo (null) Program received signal: “EXC_BAD_ACCESS”.* This seems to be courtesy of NSSortDescriptor *sortByTotals = [[NSSortDescriptor alloc] initWithKey:@"categoryTotal" ascending:sortOrder]; If I remove this everything works as expected, but obviously without the sorting I want. I'm guessing this is to do with the sorting order changing due to categoryTotal changing (deletion / insertion) but can't find away fix this. I've verified that values are being modified correctly in the second view, so it appears down to the fetchedResultsController being confused. If the categoryAmount is changed to one that does not change the sort order, then no error is generated I'm not physically changing (ie deleting) the number of items the fetchedResultsController is returning ... the only other issue I can find that seem to generate this error Any ideas would be most welcome Thanks, AJ

  Read the article

• Is Abstract Factory Pattern implemented correctly for given scenario.... ???

  - by Amit

  First thing... I am novice to pattern world, so correct me if wrong anywhere Scenario: There are multiple companies providing multiple products of diff size so there are 3 entities i.e. Companies, Their Product and size of product I have implement Abstract Pattern on this i.e. so that I will create instance of IProductFactory interface to get desired product... Is below implementation of Abstract Factory Pattern correct ??? If not then please correct the approach + Also tell me if any other pattern can be used for such scenario Thanks in advance... public enum Companies { Samsung = 0, LG = 1, Philips = 2, Sony = 3 } public enum Product { PlasmaTv = 0, DVD = 1 } public enum ProductSize { FortyTwoInch, FiftyFiveInch } interface IProductFactory { IPhilips GetPhilipsProduct(); ISony GetSonyProduct(); } interface ISony { string CreateProducts(Product product, ProductSize size); } interface IPhilips { string CreateProducts(Product product, ProductSize size); } class ProductFactory : IProductFactory { public IPhilips GetPhilipsProduct() { return new Philips(); } public ISony GetSonyProduct() { return new Sony(); } } class Philips : IPhilips { #region IPhilips Members public string CreateProducts(Product product, ProductSize size) {// I have ingnore size for now.... string output = string.Empty; if (product == Product.PlasmaTv) { output = "Plasma TV Created !!!"; } else if (product == Product.DVD) { output = "DVD Created !!!"; } return output; } #endregion } class Sony : ISony {// I have ingnore size for now.... #region ISony Members public string CreateProducts(Product product, ProductSize size) { string output = string.Empty; if (product == Product.PlasmaTv) { output = "Plasma TV Created !!!"; } else if (product == Product.DVD) { output = "DVD Created !!!"; } return output; } #endregion } IProductFactory prodFactory = new ProductFactory(); IPhilips philipsObj = prodFactory.GetPhilipsProduct(); MessageBox.Show(philipsObj.CreateProducts(Product.DVD, ProductSize.FortyTwoInch)); or //ISony sonyObj = prodFactory.GetSonyProduct(); //MessageBox.Show(sonyObj.CreateProducts(Product.DVD, ProductSize.FortyTwoInch));

  Read the article

• How to cache queries in EJB and return result efficient (performance POV)

  - by Maxym

  I use JBoss EJB 3.0 implementation (JBoss 4.2.3 server) At the beginning I created native query all the time using construction like Query query = entityManager.createNativeQuery("select * from _table_"); Of couse it is not that efficient, I performed some tests and found out that it really takes a lot of time... Then I found a better way to deal with it, to use annotation to define native queries: @NamedNativeQuery( name = "fetchData", value = "select * from _table_", resultClass=Entity.class ) and then just use it Query query = entityManager.createNamedQuery("fetchData"); the performance of code line above is two times better than where I started from, but still not that good as I expected... then I found that I can switch to Hibernate annotation for NamedNativeQuery (anyway, JBoss's implementation of EJB is based on Hibernate), and add one more thing: @NamedNativeQuery( name = "fetchData2", value = "select * from _table_", resultClass=Entity.class, readOnly=true) readOnly - marks whether the results are fetched in read-only mode or not. It sounds good, because at least in this case of mine I don't need to update data, I wanna just fetch it for report. When I started server to measure performance I noticed that query without readOnly=true (by default it is false) returns result with each iteration better and better, and at the same time another one (fetchData2) works like "stable" and with time difference between them is shorter and shorter, and after 5 iterations speed of both was almost the same... The questions are: 1) is there any other way to speed query using up? Seems that named queries should be prepared once, but I can't say it... In fact if to create query once and then just use it it would be better from performance point of view, but it is problematic to cache this object, because after creating query I can set parameters (when I use ":variable" in query), and it changes query object (isn't it?). well, is here any way to cache them? Or named query is the best option I can use? 2) any other approaches how to make results retrieveng faster. I mean, for instance I don't need those Entities to be attached, I won't update them, all I need is just fetch collection of data. Maybe readOnly is the only available way, so I can't speed it up, but who knows :) P.S. I don't ask about DB performance, all I need now is how not to create query all the time, so use it efficient, and to "allow" EJB to do less job with the same result concerning data returning.

  Read the article

• Hierarchy inheritance

  - by reito

  I had faced the problem. In my C++ hierarchy tree I have two branches for entities of difference nature, but same behavior - same interface. I created such hierarchy trees (first in image below). And now I want to work with Item or Base classes independetly of their nature (first or second). Then I create one abstract branch for this use. My mind build (second in image below). But it not working. Working scheme seems (third in image below). It's bad logic, I think... Do anybody have some ideas about such hierarchy inheritance? How make it more logical? More simple for understanding? Image Sorry for my english - russian internet didn't help:) Update: You ask me to be more explicit, and I will be. In my project (plugins for Adobe Framemaker) I need to work with dialogs and GUI controls. In some places I working with WinAPI controls, and some other places with FDK (internal Framemaker) controls, but I want to work throw same interface. I can't use one base class and inherite others from it, because all needed controls - is a hierarchy tree (not one class). So I have one hierarchy tree for WinAPI controls, one for FDK and one abstract tree to use anyone control. For example, there is an Edit control (WinEdit and FdkEdit realization), a Button control (WinButton and FdkButton realization) and base entity - Control (WinControl and FdkControl realization). For now I can link my classes in realization trees (Win and Fdk) with inheritence between each of them (WinControl is base class for WinButton and WinEdit; FdkControl is base class for FdkButton and FdkEdit). And I can link to abstract classes (Control is base class for WinControl and FdkControl; Edit is base class for WinEdit and FdkEdit; Button is base class for WinButton and FdkButton). But I can't link my abstract tree - compiler swears. In fact I have two hierarchy trees, that I want to inherite from another one. Update: I have done this quest! :) I used the virtual inheritence and get such scheme (http://img12.imageshack.us/img12/7782/99614779.png). Abstract tree has only absolute abstract methods. All inheritence in abstract tree are virtual. Link from realization tree to abstract are virtual. On image shown only one realization tree for simplicity. Thanks for help!

  Read the article

• How to create an entity with a composite primary key containing a generated value.

  - by David

  Using Hibernate + annotations, I'm trying to do the following: Two entities, Entity1 and Entity2. Entity1 contains a simple generated value primary key. Entity2 primary key is composed by a simple generated value + the id of entity one (with a many to one relationship) Unfortunately, I can't make it work. Here is an excerpt of the code: @Entity public class Entity1 { @Id @GeneratedValue private Long id; private String name; ... } @Entity public class Entity2 { @EmbeddedId private Entity2PK pk = new Entity2PK(); private String miscData; ... } @Embeddable public class Entity2PK implements Serializable { @GeneratedValue private Long id; @ManyToOne private Entity1 entity; } void test() { Entity1 e1 = new Entity1(); e1.setName("nameE1"); Entity2 e2 = new Entity2(); e2.setEntity1(e1); e2.setMiscData("test"); Transaction transaction = session.getTransaction(); try { transaction.begin(); session.save(e1); session.save(e2); transaction.commit(); } catch (Exception e) { transaction.rollback(); } finally { session.close(); } } When I run the test method I get the following errors: Hibernate: insert into Entity1 (id, name) values (null, ?) Hibernate: call identity() Hibernate: insert into Entity2 (miscData, entity_id, id) values (?, ?, ?) 07-Jun-2010 10:51:11 org.hibernate.util.JDBCExceptionReporter logExceptions WARNING: SQL Error: 0, SQLState: null 07-Jun-2010 10:51:11 org.hibernate.util.JDBCExceptionReporter logExceptions SEVERE: failed batch 07-Jun-2010 10:51:11 org.hibernate.event.def.AbstractFlushingEventListener performExecutions SEVERE: Could not synchronize database state with session org.hibernate.exception.GenericJDBCException: Could not execute JDBC batch update at org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:103) at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:91) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43) at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:254) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:266) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:167) at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:298) at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:27) at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1001) at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:339) at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:106) at test.App.main(App.java:32) Caused by: java.sql.BatchUpdateException: failed batch at org.hsqldb.jdbc.jdbcStatement.executeBatch(Unknown Source) at org.hsqldb.jdbc.jdbcPreparedStatement.executeBatch(Unknown Source) at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:48) at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:247) ... 8 more Note that I use HSQLDB. Any ideas about what is wrong ?

  Read the article

• Passing ViewModel for backbone.js from MVC3 Server-Side

  - by Roman

  In ASP.NET MVC there is Model, View and Controller. MODEL represents entities which are stored in database and essentially is all the data used in a application (for example, generated by EntityFramework, "DB First" approach). Not all data from model you want to show in the view (for example, hashs of passwords). So you create VIEW MODEL, each for every strongly-typed-razor-view you have in application. Like this: using System; using System.Collections.Generic; using System.Linq; using System.Web; namespace MyProject.ViewModels.SomeController.SomeAction { public class ViewModel { public ViewModel() { Entities1 = new List<ViewEntity1>(); Entities2 = new List<ViewEntity2>(); } public List<ViewEntity1> Entities1 { get; set; } public List<ViewEntity2> Entities2 { get; set; } } public class ViewEntity1 { //some properties from original DB-entity you want to show } public class ViewEntity2 { } } When you create complex client-side interfaces (I do), you use some pattern for javascript on client, MVC or MVVM (I know only these). So, with MVC on client you have another model (Backbone.Model for example), which is third model in application. It is a bit much. Why don`t we use the same ViewModel model on a client (in backbone.js or another framework)? Is there a way to transfer CS-coded model to JS-coded? Like in MVVM pattern, with knockout.js, when you can do like this: in SomeAction.cshtml: <div style="display: none;" id="view_model">@Json.Encode(Model)</div> after that in Javascript-code var ViewModel = ko.mapping.fromJSON($("#view_model").get(0).innerHTML); now you can extend your ViewModel with some actions, event handlers, etc: ko.utils.extend(ViewModel, { some_function: function () { //some code } }); So, we are not building the same view model on the client again, we are transferring existing view model from server. At least, data. But knockout.js is not suitable for me, you can`t build complex UI with it, it is just data-binding. I need something more structural, like backbone.js. The only way to build ViewModel for backbone.js I can see now is re-writing same ViewModel in JS from server with hands. Is there any ways to transfer it from server? To reuse the same viewmodel on server view and client view?

  Read the article

• Getting field of type bytea in helper table when using GenerationType.IDENTITY

  - by dtrunk

  I'm creating my db scheme using Hibernate. There's a Table called "tbl_articles" and another one called "tbl_categories". To have a n-n relationship a helper table ("tbl_articles_categories") is needed. Here are all necessary Entities: @Entity @Table( name = "tbl_articles" ) public class Article implements Serializable { private static final long serialVersionUID = 1L; @Id @Column( nullable = false ) @GeneratedValue( strategy = GenerationType.IDENTITY ) private Integer id; // other fields... public Integer getId() { return id; } public void setId( Integer id ) { this.id = id; } // other fields... } @Entity @Table( name = "tbl_categories" ) public class Category implements Serializable { private static final long serialVersionUID = 1L; @Id @Column( nullable = false ) @GeneratedValue( strategy = GenerationType.IDENTITY ) private Integer id; // other fields public Integer getId() { return id; } public void setId( Integer id ) { this.id = id; } // other fields... } @Entity @Table( name = "tbl_articles_categories" ) @AssociationOverrides({ @AssociationOverride( name = "pk.article", joinColumns = @JoinColumn( name = "article_id" ) ), @AssociationOverride( name = "pk.category", joinColumns = @JoinColumn( name = "category_id" ) ) }) public class ArticleCategory { private ArticleCategoryPK pk = new ArticleCategoryPK(); public void setPk( ArticleCategoryPK pk ) { this.pk = pk; } @EmbeddedId public ArticleCategoryPK getPk() { return pk; } @Transient public Article getArticle() { return pk.getArticle(); } public void setArticle( Article article ) { pk.setArticle( article ); } @Transient public Category getCategory() { return pk.getCategory(); } public void setCategory( Category category ) { pk.setCategory( category ); } } @Embeddable public class ArticleCategoryPK implements Serializable { private static final long serialVersionUID = 1L; @ManyToOne @ForeignKey( name = "tbl_articles_categories_fkey_article_id" ) private Article article; @ManyToOne @ForeignKey( name = "tbl_articles_categories_fkey_category_id" ) private Category category; public ArticleCategoryPK( Article article, Category category ) { setArticle( article ); setCategory( category ); } public ArticleCategoryPK() { } public Article getArticle() { return article; } public void setArticle( Article article ) { this.article = article; } public Category getCategory() { return category; } public void setCategory( Category category ) { this.category = category; } } Now, I'm getting a serial type what I wanted in my articles table as well as in my categories table. But looking into my helper table, there aren't the expected fields article_id and category_id each of type integer - instead there are article and category of type bytea. What's wrong here? EDIT: Sorry, forgot to mention that I'm using PostgreSQL.

  Read the article

• NHibernate - Saving simple parent-child relationship generates unnecessary selects with assigned id

  - by Alice

  Entities: public class Parent { virtual public long Id { get; set; } virtual public string Description { get; set; } virtual public ICollection<Child> Children { get; set; } } public class Child { virtual public long Id { get; set; } virtual public string Description { get; set; } virtual public Parent Parent { get; set; } } Mappings: public class ParentMap : ClassMap<Parent> { public ParentMap() { Id(x => x.Id).GeneratedBy.Assigned(); Map(x => x.Description); HasMany(x => x.Children) .AsSet() .Inverse() .Cascade.AllDeleteOrphan(); } } public class ChildMap : ClassMap<Child> { public ChildMap() { Id(x => x.Id).GeneratedBy.Assigned(); Map(x => x.Description); References(x => x.Parent) .Not.Nullable() .Cascade.All(); } } and using (var session = sessionFactory.OpenSession()) using (var transaction = session.BeginTransaction()) { var parent = new Parent { Id = 1 }; parent.Children = new HashSet<Child>(); var child1 = new Child { Id = 2, Parent = parent }; var child2 = new Child { Id = 3, Parent = parent }; parent.Children.Add(child1); parent.Children.Add(child2); session.Save(parent); transaction.Commit(); } this codes generates following sql NHibernate: SELECT child_.Id, child_.Description as Descript2_0_, child_.Parent_id as Parent3_0_ FROM [Child] child_ WHERE child_.Id=@p0;@p0 = 2 [Type: Int64 (0)] NHibernate: SELECT child_.Id, child_.Description as Descript2_0_, child_.Parent_id as Parent3_0_ FROM [Child] child_ WHERE child_.Id=@p0;@p0 = 3 [Type: Int64 (0)] NHibernate: INSERT INTO [Parent] (Description, Id) VALUES (@p0, @p1);@p0 = NULL[Type: String (4000)], @p1 = 1 [Type: Int64 (0)] NHibernate: INSERT INTO [Child] (Description, Parent_id, Id) VALUES (@p0, @p1, @p2);@p0 = NULL [Type: String (4000)], @p1 = 1 [Type: Int64 (0)], @p2 = 2 [Type:Int64 (0)] NHibernate: INSERT INTO [Child] (Description, Parent_id, Id) VALUES (@p0, @p1, @p2);@p0 = NULL [Type: String (4000)], @p1 = 1 [Type: Int64 (0)], @p2 = 3 [Type:Int64 (0)] Why are these two selects generated and how can I remove it?

  Read the article

• Refactoring Singleton Overuse

  - by drharris

  Today I had an epiphany, and it was that I was doing everything wrong. Some history: I inherited a C# application, which was really just a collection of static methods, a completely procedural mess of C# code. I refactored this the best I knew at the time, bringing in lots of post-college OOP knowledge. To make a long story short, many of the entities in code have turned out to be Singletons. Today I realized I needed 3 new classes, which would each follow the same Singleton pattern to match the rest of the software. If I keep tumbling down this slippery slope, eventually every class in my application will be Singleton, which will really be no logically different from the original group of static methods. I need help on rethinking this. I know about Dependency Injection, and that would generally be the strategy to use in breaking the Singleton curse. However, I have a few specific questions related to this refactoring, and all about best practices for doing so. How acceptable is the use of static variables to encapsulate configuration information? I have a brain block on using static, and I think it is due to an early OO class in college where the professor said static was bad. But, should I have to reconfigure the class every time I access it? When accessing hardware, is it ok to leave a static pointer to the addresses and variables needed, or should I continually perform Open() and Close() operations? Right now I have a single method acting as the controller. Specifically, I continually poll several external instruments (via hardware drivers) for data. Should this type of controller be the way to go, or should I spawn separate threads for each instrument at the program's startup? If the latter, how do I make this object oriented? Should I create classes called InstrumentAListener and InstrumentBListener? Or is there some standard way to approach this? Is there a better way to do global configuration? Right now I simply have Configuration.Instance.Foo sprinkled liberally throughout the code. Almost every class uses it, so perhaps keeping it as a Singleton makes sense. Any thoughts? A lot of my classes are things like SerialPortWriter or DataFileWriter, which must sit around waiting for this data to stream in. Since they are active the entire time, how should I arrange these in order to listen for the events generated when data comes in? Any other resources, books, or comments about how to get away from Singletons and other pattern overuse would be helpful.

  Read the article

< Previous Page | 90 91 92 93 94 95 96 97 98 99 100 101  | Next Page >