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  • The member [class] has no supported translation to SQL

    - by Code Sherpa
    Hi, I am getting the following error: Error Message:The member 'Company.ProductCore.Core.Domain.Account.Email' has no supported translation to SQL. My method looks like this: public Account GetAccountByEmail(string email) { Account account; using (WorkbookDataContext dc = _conn.GetContext()) { account = ( from a in dc.Accounts join em in dc.Emails on a.AccountId equals em.AccountId where a.Email.EmailAddress == email select a).FirstOrDefault(); } return account; } My Account class has a getter / setter that exposes Email: public Email Email { get { return _email; } set { _email = value; } } And my Email is a LINQ object. I have a feeling that the problem is that I am using a LINQ object for me Email property? I am new to LINQ and am not really sure why this is happening. Help appreciated, thanks...

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  • MVC more specified models should be populated by more precise query too?

    - by KevinUK
    If you have a Car model with 20 or so properties (and several table joins) for a carDetail page then your LINQ to SQL query will be quite large. If you have a carListing page which uses under 5 properties (all from 1 table) then you use a CarSummary model. Should the CarSummary model be populated using the same query as the Car model? Or should you use a separate LINQ to SQL query which would be more precise? I am just thinking of performance but LINQ uses lazy loading anyway so I am wondering if this is an issue or not.

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  • Hibernate: deletes not cascading for self-referencing entities

    - by jwaddell
    I have the following (simplified) Hibernate entities: @Entity @Table(name = "package") public abstract class Package { protected Content content; @ManyToOne(cascade = {javax.persistence.CascadeType.ALL}) @JoinColumn(name = "content_id") @Fetch(value = FetchMode.JOIN) public Content getContent() { return content; } public void setContent(Content content) { this.content = content; } } @Entity @Table(name = "content") public class Content { private Set<Content> subContents = new HashSet<Content>(); @ManyToMany(fetch = FetchType.EAGER) @JoinTable(name = "subcontents", joinColumns = {@JoinColumn(name = "content_id")}, inverseJoinColumns = {@JoinColumn(name = "elt")}) @Cascade(value = {org.hibernate.annotations.CascadeType.DELETE, org.hibernate.annotations.CascadeType.REPLICATE}) @Fetch(value = FetchMode.SUBSELECT) public Set<Content> getSubContents() { return subContents; } public void setSubContents(Set<Content> subContents) { this.subContents = subContents; } } So a Package has a Content, and a Content is self-referencing in that it has many sub-Contents (which may contain sub-Contents of their own etc). The relationships are required to be ManyToOne (Package to Content) and ManyToMany (Content to sub-Contents) but for the case I am currently testing each sub-Content only relates to one Package or Content. The problem is that when I delete a Package and flush the session, I get a Hibernate error stating that I'm violating a foreign key constraint on table subcontents, with a particular content_id still referenced from table subcontents. I've tried specifically (recursively) deleting the Contents before deleting the Package but I get the same error. Is there a reason why this entity tree is not being deleted properly?

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  • How to load entities into readonly collections using the entity framework

    - by Anton P
    I have a POCO domain model which is wired up to the entity framework using the new ObjectContext class. public class Product { private ICollection<Photo> _photos; public Product() { _photos = new Collection<Photo>(); } public int Id { get; set; } public string Name { get; set; } public virtual IEnumerable<Photo> Photos { get { return _photos; } } public void AddPhoto(Photo photo) { //Some biz logic //... _photos.Add(photo); } } In the above example i have set the Photos collection type to IEnumerable as this will make it read only. The only way to add/remove photos is through the public methods. The problem with this is that the Entity Framework cannot load the Photo entities into the IEnumerable collection as it's not of type ICollection. By changing the type to ICollection will allow callers to call the Add mentod on the collection itself which is not good. What are my options?

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  • Two entities with @ManyToOne should join the same table

    - by Ivan Yatskevich
    I have the following entities Student @Entity public class Student implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; //getter and setter for id } Teacher @Entity public class Teacher implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; //getter and setter for id } Task @Entity public class Task implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; @ManyToOne(optional = false) @JoinTable(name = "student_task", inverseJoinColumns = { @JoinColumn(name = "student_id") }) private Student author; @ManyToOne(optional = false) @JoinTable(name = "student_task", inverseJoinColumns = { @JoinColumn(name = "teacher_id") }) private Teacher curator; //getters and setters } Consider that author and curator are already stored in DB and both are in the attached state. I'm trying to persist my Task: Task task = new Task(); task.setAuthor(author); task.setCurator(curator); entityManager.persist(task); Hibernate executes the following SQL: insert into student_task (teacher_id, id) values (?, ?) which, of course, leads to null value in column "student_id" violates not-null constraint Can anyone explain this issue and possible ways to resolve it?

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  • Two entities with @ManyToOne joins the same table

    - by Ivan Yatskevich
    I have the following entities Student @Entity public class Student implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; //getter and setter for id } Teacher @Entity public class Teacher implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; //getter and setter for id } Task @Entity public class Task implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; @ManyToOne(optional = false) @JoinTable(name = "student_task", inverseJoinColumns = { @JoinColumn(name = "student_id") }) private Student author; @ManyToOne(optional = false) @JoinTable(name = "student_task", inverseJoinColumns = { @JoinColumn(name = "teacher_id") }) private Teacher curator; //getters and setters } Consider that author and curator are already stored in DB and both are in the attached state. I'm trying to persist my Task: Task task = new Task(); task.setAuthor(author); task.setCurator(curator); entityManager.persist(task); Hibernate executes the following SQL: insert into student_task (teacher_id, id) values (?, ?) which, of course, leads to null value in column "student_id" violates not-null constraint Can anyone explain this issue and possible ways to resolve it?

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  • Java/Hibernate using interfaces over the entities.

    - by Dennetik
    I am using annoted Hibernate, and I'm wondering whether the following is possible. I have to set up a series of interfaces representing the objects that can be persisted, and an interface for the main database class containing several operations for persisting these objects (... an API for the database). Below that, I have to implement these interfaces, and persist them with Hibernate. So I'll have, for example: public interface Data { public String getSomeString(); public void setSomeString(String someString); } @Entity public class HbnData implements Data, Serializable { @Column(name = "some_string") private String someString; public String getSomeString() { return this.someString; } public void setSomeString(String someString) { this.someString = someString; } } Now, this works fine, sort of. The trouble comes when I want nested entities. The interface of what I'd want is easy enough: public interface HasData { public Data getSomeData(); public void setSomeData(Data someData); } But when I implement the class, I can follow the interface, as below, and get an error from Hibernate saying it doesn't know the class "Data". @Entity public class HbnHasData implements HasData, Serializable { @OneToOne(cascade = CascadeType.ALL) private Data someData; public Data getSomeData() { return this.someData; } public void setSomeData(Data someData) { this.someData = someData; } } The simple change would be to change the type from "Data" to "HbnData", but that would obviously break the interface implementation, and thus make the abstraction impossible. Can anyone explain to me how to implement this in a way that it will work with Hibernate?

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  • Using SimpleDB (with SimpleSavant) with POCO / existing entities, not attributes on my classes

    - by alex
    I'm trying to use Simple Savant within my application, to use SimpleDB I currently have (for example) public class Person { public Guid Id { get; set; } public string Name { get; set; } public string Description { get; set; } public DateTime DateOfBirth { get; set; } } To use this with Simple Savant, i'd have to put attributes above the class declaration, and property - [DomainName("Person")] above the class, and [ItemName] above the Id property. I have all my entities in a seperate assembly. I also have my Data access classes an a seperate assembly, and a class factory selects, based on config, the IRepository (in this case, IRepository I want to be able to use my existing simple class - without having attributes on the properties etc.. In case I switch out of simple db, to something else - then I only need to create a different implementation of IRepository. Should I create a "DTO" type class to map the two together? Is there a better way?

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  • FullCalendar/JSON event feed problem

    - by n4rc1ssus
    I am using a php/MySQL driven event feed to JSON. I am also trying to use greek html entities (i.e. &Gamma-with the semicolon) in the title for the event. Because FullCalendar will not let me see all the processies in firebug I can't see exactly what is going on but it will not render the Γ, etc. I have tried all the combinations I can think of in the php json_encode, the actual MySQL db field result. QTip which fullCalendar recommended on their site actually renders it correctly in the tip rendering. I am at a loss because this is something I really wish to use in the app if at all possible. Any help would be greatly appreciated. Slight Update I finally found that the JSON is being manipulated to make the & itself into &amp';' no matter what I do; so any relevant info on this could come in handy also. Thx

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  • Entity Frameworks 4 - Changing the model does not update the T4 self tracking template files

    - by Darren
    I am using self tracking entities and have moved the entity classes to another assembly by using 'Add as link' to point to the TT file as mentioned here. Now though, when I update the model (for instance change a property name) the template is not automatically run and so the entity class does not get updated. I can of course manually run the template to get the updates, but it would be easier if it ran automatically in the way it did before I moved the classes. Is there any way to achieve this? Darren.

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  • NullReferenceException in EntityFramework, how come?

    - by Mickel
    Take a look at this query: var user = GetUser(userId); var sessionInvites = ctx.SessionInvites .Include("InvitingUser") .Include("InvitedUser") .Where(e => e.InvitedUser.UserId == user.UserId) .ToList(); var invites = sessionInvites; // Commenting out the two lines below, and it works as expected. foreach (var invite in sessionInvites) ctx.DeleteObject(invite); ctx.SaveChanges(); return invites; Now, everything here executes without any errors. The invites that exists for the user are being deleted and the invites are being returned with success. However, when I then try to navigate to either InvitingUser or InvitedUser on any of the returned invites, I get NullReferenceException. All other properties of the SessionIvites returned, works fine. How come? [EDIT] Now the weird thing is, if I comment out the lines with delete it works as expected. (Except that the entities will not get deleted :S)

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  • Get records based on child condition

    - by Shawn Mclean
    In LINQ To Entities: How do I get the records (including both child and parent) based on a condition of the child in a one to many. My structure is set up as follows: GetResources() - returns a list of Resources. GetResources().ResourceNames - this is the child, which is an entity collection. GetResources().ResourceNames - a property of one record of this child is Name. I'd like to construct something like this: return (from p in repository.GetResources() where p.ResourceNames.Exist(r => r.Name.Contains(text, StringComparison.CurrentCultureIgnoreCase)) select p).ToList(); but of course, Exist doesn't exist. thanks.

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  • Is Linq having a mind-numbing effect on .NET programmers?

    - by Aaronaught
    A lot of us started seeing this phenomenon with jQuery about a year ago when people started asking how to do absolutely insane things like retrieve the query string with jQuery. The difference between the library (jQuery) and the language (JavaScript) is apparently lost on many programmers, and results in a lot of inappropriate, convoluted code being written where it is not necessary. Maybe it's just my imagination, but I swear I'm starting to see an uptick in the number of questions where people are asking to do similarly insane things with Linq, like find ranges in a sorted array. I can't get over how thoroughly inappropriate the Linq extensions are for solving that problem, but more importantly the fact that the author just assumed that the ideal solution would involve Linq without actually thinking about it (as far as I can tell). It seems that we are repeating history, breeding a new generation of .NET programmers who can't tell the difference between the language (C#/VB.NET) and the library (Linq). What is responsible for this phenomenon? Is it just hype? Magpie tendencies? Has Linq picked up a reputation as a form of magic, where instead of actually writing code you just have to utter the right incantation? I'm hardly satisfied with those explanations but I can't really think of anything else. More importantly, is it really a problem, and if so, what's the best way to help enlighten these people?

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  • Deletes not cascading for self-referencing entities

    - by jwaddell
    I have the following (simplified) Hibernate entities: @Entity @Table(name = "package") public class Package { protected Content content; @OneToOne(cascade = {javax.persistence.CascadeType.ALL}) @JoinColumn(name = "content_id") @Fetch(value = FetchMode.JOIN) public Content getContent() { return content; } public void setContent(Content content) { this.content = content; } } @Entity @Table(name = "content") public class Content { private Set<Content> subContents = new HashSet<Content>(); private ArchivalInformationPackage parentPackage; @OneToMany(fetch = FetchType.EAGER) @JoinTable(name = "subcontents", joinColumns = {@JoinColumn(name = "content_id")}, inverseJoinColumns = {@JoinColumn(name = "elt")}) @Cascade(value = {org.hibernate.annotations.CascadeType.DELETE, org.hibernate.annotations.CascadeType.REPLICATE}) @Fetch(value = FetchMode.SUBSELECT) public Set<Content> getSubContents() { return subContents; } public void setSubContents(Set<Content> subContents) { this.subContents = subContents; } @ManyToOne(cascade = {CascadeType.ALL}) @JoinColumn(name = "parent_package_id") public Package getParentPackage() { return parentPackage; } public void setParentPackage(Package parentPackage) { this.parentPackage = parentPackage; } } So there is one Package, which has one "top" Content. The top Content links back to the Package, with cascade set to ALL. The top Content may have many "sub" Contents, and each sub-Content may have many sub-Contents of its own. Each sub-Content has a parent Package, which may or may not be the same Package as the top Content (ie a many-to-one relationship for Content to Package). The relationships are required to be ManyToOne (Package to Content) and ManyToMany (Content to sub-Contents) but for the case I am currently testing each sub-Content only relates to one Package or Content. The problem is that when I delete a Package and flush the session, I get a Hibernate error stating that I'm violating a foreign key constraint on table subcontents, with a particular content_id still referenced from table subcontents. I've tried specifically (recursively) deleting the Contents before deleting the Package but I get the same error. Is there a reason why this entity tree is not being deleted properly? EDIT: After reading answers/comments I realised that a Content cannot have multiple Packages, and a sub-Content cannot have multiple parent-Contents, so I have modified the annotations from ManyToOne and ManyToMany to OneToOne and OneToMany. Unfortunately that did not fix the problem. I have also added the bi-directional link from Content back to the parent Package which I left out of the simplified code.

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  • How to load entities into private collections using the entity framework

    - by Anton P
    I have a POCO domain model which is wired up to the entity framework using the new ObjectContext class. public class Product { private ICollection<Photo> _photos; public Product() { _photos = new Collection<Photo>(); } public int Id { get; set; } public string Name { get; set; } public virtual IEnumerable<Photo> Photos { get { return _photos; } } public void AddPhoto(Photo photo) { //Some biz logic //... _photos.Add(photo); } } In the above example i have set the Photos collection type to IEnumerable as this will make it read only. The only way to add/remove photos is through the public methods. The problem with this is that the Entity Framework cannot load the Photo entities into the IEnumerable collection as it's not of type ICollection. By changing the type to ICollection will allow callers to call the Add mentod on the collection itself which is not good. What are my options? Edit: I could refactor the code so it does not expose a public property for Photos: public class Product { public Product() { Photos = new Collection<Photo>(); } public int Id { get; set; } public string Name { get; set; } private Collection<Photo> Photos {get; set; } public IEnumerable<Photo> GetPhotos() { return Photos; } public void AddPhoto(Photo photo) { //Some biz logic //... Photos.Add(photo); } } And use the GetPhotos() to return the collection. The other problem with the approach is that I will loose the change tracking abilities as I cannot mark the collection as Virtual - It is not possible to mark a property as private virtual. In NHibernate I believe it's possible to map the proxy class to the private collection via configuration. I hope that this will become a feature of EF4. Currently i don't like the inability to have any control over the collection!

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  • Classes to Entities; Like-class inheritence problems

    - by Stacey
    Beyond work, some friends and I are trying to build a game of sorts; The way we structure some of it works pretty well for a normal object oriented approach, but as most developers will attest this does not always translate itself well into a database persistent approach. This is not the absolute layout of what we have, it is just a sample model given for sake of representation. The whole project is being done in C# 4.0, and we have every intention of using Entity Framework 4.0 (unless Fluent nHibernate can really offer us something we outright cannot do in EF). One of the problems we keep running across is inheriting things in database models. Using the Entity Framework designer, I can draw the same code I have below; but I'm sure it is pretty obvious that it doesn't work like it is expected to. To clarify a little bit; 'Items' have bonuses, which can be of anything. Therefore, every part of the game must derive from something similar so that no matter what is 'changed' it is all at a basic enough level to be hooked into. Sounds fairly simple and straightforward, right? So then, we inherit everything that pertains to the game from 'Unit'. Weights, Measures, Random (think like dice, maybe?), and there will be other such entities. Some of them are similar, but in code they will each react differently. We're having a really big problem with abstracting this kind of thing into a database model. Without 'Enum' support, it is proving difficult to translate into multiple tables that still share a common listing. One solution we've depicted is to use a 'key ring' type approach, where everything that attaches to a character is stored on a 'Ring' with a 'Key', where each Key has a Value that represents a type. This works functionally but we've discovered it becomes very sluggish and performs poorly. We also dislike this approach because it begins to feel as if everything is 'dumped' into one class; which makes management and logical structure difficult to adhere to. I was hoping someone else might have some ideas on what I could do with this problem. It's really driving me up the wall; To summarize; the goal is to build a type (Unit) that can be used as a base type (Table per Type) for generic reference across a relatively global scope, without having to dump everything into a single collection. I can use an Interface to determine actual behavior so that isn't too big of an issue. This is 'roughly' the same idea expressed in the Entity Framework.

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  • Correct way to use Drupal 7 Entities and Field API

    - by Martin Petts
    I'm trying to use Drupal 7's entities and field API to correctly build a new module. What I have been unable to understand from the documentation is the correct way to use the new API to create a 'content type' (not a node type) with a number of set fields, such as Body. I'm trying to set up the entity using hook_entity_info, then I believe I need to add the body field using field_create_instance, but I can't seem to get it to work. In mycontenttype.module: /** * Implements hook_entity_info(). */ function mycontenttype_entity_info() { $return = array( 'mycontenttype' => array( 'label' => t('My Content Type'), 'controller class' => 'MyContentTypeEntityController', 'base table' => 'content_type', 'uri callback' => 'content_type_uri', 'entity keys' => array( 'id' => 'cid', 'label' => 'title' ), 'bundles' => array( 'mycontenttype' => array( 'label' => 'My Content Type', 'admin' => array( 'path' => 'admin/contenttype', 'access arguments' => array('administer contenttype') ) ) ), 'fieldable' => true ) ); return $return; } /** * Implements hook_field_extra_fields(). */ function mycontenttype_field_extra_fields() { $return['mycontenttype']['mycontenttype'] = array( 'form' = array( 'body' = array( 'label' = 'Body', 'description' = t('Body content'), 'weight' = 0, ), ), ); return $return; } Then does this go in the .install file? function mycontenttype_install() { $field = array( 'field_name' => 'body', 'type' => 'text_with_summary', 'entity_types' => array('survey'), 'translatable' => TRUE, ); field_create_field($field); $instance = array( 'entity_type' => 'mycontenttype', 'field_name' => 'body', 'bundle' => 'mycontenttype', 'label' => 'Body', 'widget_type' => 'text_textarea_with_summary', 'settings' => array('display_summary' => TRUE), 'display' => array( 'default' => array( 'label' => 'hidden', 'type' => 'text_default', ), 'teaser' => array( 'label' => 'hidden', 'type' => 'text_summary_or_trimmed', ) ) ); field_create_instance($instance); }

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  • Using LIKE operator in LINQ to Entity

    - by Draconic
    Hi, everybody! Currently in our project we are using Entity Framework and LINQ. We want to create a search feature where the Client fills different filters but he isn't forced to. To do this "dynamic" query in LINQ, we thought about using the Like operator, searching either for the field, or "%" to get everything if the user didn't fill that field. The joke's on us when we discovered it didn't support Like. After some searching, we read several answers where it's sugested to use StartsWith, but it's useless for us. Is the only solution using something like: ObjectQuery<Contact> contacts = db.Contacts; if (pattern != "") { contacts = contacts.Where(“it.Name LIKE @pattern”); contacts.Parameters.Add(new ObjectParameter(“pattern”, pattern); } However, we'd like to stick with linq only. Happy coding!

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  • Is writing eSQL database agnostic?

    - by Robert Koritnik
    Using EF we can use LINQ to read data which is rather simple (especialy using fluent calls), but we have less control unless we write eSQL on our own. Is writing eSQL database actually data store independant code? So if we decide to change data store, can the same statements still be used? Is writing eSQL strings in your code pose any serious security threats similar to writing TSQL statements in plain strings? So we moved to SPs. Could we still mode eSQL scripts outside of code as well and use some other technique to make them a bit more secure?

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  • Is writing eSQL database independent or not?

    - by Robert Koritnik
    Using EF we can use LINQ to read data which is rather simple (especially using fluent calls), but we have less control unless we write eSQL on our own. Is writing eSQL actually data store independent code? So if we decide to change data store, can the same statements still be used? Does writing eSQL strings in your code pose any serious security threats similar to writing TSQL statements as plain strings in C# code? That's why SPs are recommended. Could we still move eSQL scripts outside of code and use some other technique to make them a bit more secure?

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  • Is writing eSQL database independant or not?

    - by Robert Koritnik
    Using EF we can use LINQ to read data which is rather simple (especialy using fluent calls), but we have less control unless we write eSQL on our own. Is writing eSQL database actually data store independant code? So if we decide to change data store, can the same statements still be used? Is writing eSQL strings in your code pose any serious security threats similar to writing TSQL statements in plain strings? So we moved to SPs. Could we still mode eSQL scripts outside of code as well and use some other technique to make them a bit more secure?

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  • How do I delete an object from an Entity Framework model without first loading it?

    - by Tomas Lycken
    I am quite sure I've seen the answer to this question somewhere, but as I couldn't find it with a couple of searches on SO or google, I ask it again anyway... In Entity Framework, the only way to delete a data object seems to be MyEntityModel ent = new MyEntityModel(); ent.DeleteObject(theObjectToDelete); ent.SaveChanges(); However, this approach requires the object to be loaded to, in this case, the Controller first, just to delete it. Is there a way to delete a business object referencing only for instance its ID? If there is a smarter way using Linq or Lambda expressions, that is fine too. The main objective, though, is to avoid loading data just to delete it.

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  • Dynamic Data: how to filter dropdown for foreign key on edit page

    - by Leonv
    I have Organisation with a foreign key to a Manager. Managers can be active, or inactive. On the Dynamic Data edit page for Organisation, I need to filter the dropdown for Manager to only show active records. I started out by making a custom version of DynamicData\FieldTemplates\ForeignKey_Edit.ascx and setting a UIHint to the new field template on Organisation.Manager. But, how to customize the linq or sql query that runs to load the Managers? Using Linq-to-SQL and DynamicDataFutures

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  • NLOG to output db.out

    - by Coppermill
    I would like to use nLog to output my LINQ to SQL generated SQL to the log file e.g. db.Log = Console.Out reports the generated SQL to the console, http://www.bryanavery.co.uk/post/2009/03/06/Viewing-the-SQL-that-is-generated-from-LINQ-to-SQL.aspx How can I get the log to log to NLOG?

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