I set up a Generic repository using this code for update
private void AttachIfNot(TEntity entityToActive)
{
if (_dbContext.Entry(entityToActive).State == EntityState.Detached)
{
_dbSet.Attach(entityToActive);
}
}
private void UpdateEntity(TEntity entityToUpdate)
{
AttachIfNot(entityToUpdate);
_dbContext.Entry(entityToUpdate).State = EntityState.Modified;
}
It just attach the entity and set the modified state to save.
But when I use efocre ownsone to map a value object,the update entity function is not working.
I found out that it only works when I set Valueobject to modified too.
_dbContext.Entry(entityToUpdate).State = EntityState.Modified;
_dbContext.Entry(entityToUpdate.Valueobject).State = EntityState.Modified;
But It is hard for me to specify all the value objects in a Generic Repository.
This is code also has problems with one to many or other relations.
The working way is like this:
Classroom classroom = new Classroom
{
Id = 1,
Name = "b",
Students = new List<Student>
{
new Student()
{
Name = "aa",
Id = 2
}
}
};
if (_defaultDbContext.Entry(classroom).State == EntityState.Detached)
{
_defaultDbContext.Classrooms.Attach(classroom);
foreach(var stu in classroom.Students)
{
_defaultDbContext.Students.Attach(stu);
}
}
_defaultDbContext.Entry(classroom).State = EntityState.Modified;
foreach (var stu in classroom.Students)
{
_defaultDbContext.Entry(stu).State = EntityState.Modified;
}
_defaultDbContext.SaveChanges();
I found out one way is get the entity form repo then update it using automapper:
targetEntity = repo.GetById(entityId);
automapper.map(souceEntity,targetEntity);
//or
automapper.map(souceDto,targetEntity);
_dbContext.Save();
The entity comes by query, so the change will be tracked.
But I have to configure the automapper with this entity map when I want to change entity
CreateMap<EntityType, EntityType>();
I think it's not the best solution. Is there a bettere way?
DbContext.Update would be fine to fix this problem.
see:
https://www.learnentityframeworkcore.com/dbcontext/change-tracker
Related
I have the following code:
Get contact
public Contact LoadContactFromId(int contactId)
{
using(var ctx = new ContactContext())
{
var contact = ctx.Contacts.AsNoTracking().First(c => c.ContactId == contactId);
return contact;
}
}
Update Contact
public void UpdateExistingContact(Contact updatedContact)
{
using(var ctx = new ContactContext())
{
ctx.Contacts.Attach(updatedContact);
ctx.Entry(updatedContact).State = EntityState.Modified;
foreach (var item in updatedContact.ContactPoints)
{
ctx.Entry(item).State = (item.ContactPointId == 0) ? EntityState.Added : EntityState.Modified;
}
ctx.SaveChanges();
}
}
I am currently working with ASP.NET webforms and because of its stateless model, I can't keep working within the DbContext. Because of this, I end up basically recreating the entire Contact entity from the POST data and then update it.
This seems like a horrible way to do this because I lose conncurrncey resolution since I'm not working with the true original entity and it seems kind of cumbersome to always have to recreate the object.
Is there an easier way to do this? Am I looking at this all wrong?
I'm using EF5 with MVC and POCO's and need a little help
I have an update function which is passed a disconnected POCO. The POCO has a 'navigation property' collection, eg: Provider has
public virtual ICollection<Company> Companies { get; set; }
When the Provider was loaded (and the old context closed) it had two Company objects, now it has four and I'd like to update.
I thought the code below might work but Companies is not updated (but the non-navigational properties of Provider (like string Name {get;set} are still updated ok) and there is no error
public void Update(Provider entity)
{
// Existing entity
_context.Entry(entity).State = EntityState.Modified;
if (entity.Companies.Any())
{
//try to tell EF about the companies
foreach (var company in entity.Companies)
{
//the company exists already - let the context know....
_context.Entry(company).State = EntityState.Modified;
_context.Companies.Attach(company);
}
}
}
... and later: _unitOfWork.SaveChanges();
For an insert of Provider with Companies I had successfully used:
if (entity.Companies.Any())
{
//these are not to be created - they exist -
//I want EF to add them as nav properties
foreach (var company in entity.Companies)
{
//the company exists already - let the context know....
_pvpContext.Companies.Attach(company);
}
}
// New entity
_pvpContext.Entry(entity).State = EntityState.Added;
I'm going to go and read Julia Lerman's book as EF is killing me - but I'd really appreciate any help updating 'Companies' in the meantime - Thx
Edit:
Taking #Manos' kind advice I tried:
List<Company> companies = new List<Company>();
if (entity.Companies != null && entity.Companies.Any())
{
//pull out the Companies from the POCO
companies = entity.Companies.ToList();
//remove them
entity.Companies = new Collection<Company>();
entity.Companies.Clear();
}
// pass existing entity to the context, tagged as modified
_pvpContext.Entry(entity).State = EntityState.Modified;
if (companies.Any())
{
//now re-add the companies while the context is listening. ffs.
foreach (var company in companies)
{
entity.Companies.Add(company);
}
}
If I add the Provider.Companies to the context (like in the insert) I get:
Violation of PRIMARY KEY constraint 'PK__tmp_ms_x__679519B7F943FD8D'.
Cannot insert duplicate key in object 'dbo.ProviderCompany'. The
duplicate key value is (5, 3)
which is odd as there is not composite key of (provider 5, company 3) - so maybe it's trying to add it in twice here?
If I don't pre-add the Provider.Companies I get:
at System.Data.Entity.Internal.InternalContext.SaveChanges() at
System.Data.Entity.Internal.LazyInternalContext.SaveChanges() at
System.Data.Entity.DbContext.SaveChanges()
I only have 4.1 to test, but try this as a basic logic:
public void Update(Provider entity)
{
// Existing entity
Provider contextProvider = _context.Entry(entity);
contextProvider.Companies.Clear();
foreach (var company in entity.Companies)
{
contextProvider.Companies.Add(company);
}
}
This needs a little refinement in order to only add new companies as opposed to doing a complete removal and reinstatement but it should work.
Edit in response to comment:
Try catching the exception thrown by SaveChanges() with the following:
try {
_unitOfWork.SaveChanges();
} catch (System.Data.Entity.Validation.DbEntityValidationException e) {
foreach (var k in e.EntityValidationErrors) {
foreach (var e1 in k.ValidationErrors) {
Console.WriteLine("{0} - {1}", e1.PropertyName, e1.ErrorMessage);
}
}
}
It should give you a little more information to go on.
I need to update all fields except property1 and property2 for the given entity object.
Having this code:
[HttpPost]
public ActionResult Add(object obj)
{
if (ModelState.IsValid)
{
context.Entry(obj).State = System.Data.EntityState.Modified;
context.SaveChanges();
}
return View(obj);
}
How to change it to add an exception to obj.property1 and obj.property2 for not being updated with this code?
Let's assume that you have a collection of the properties to be excluded:
var excluded = new[] { "property1", "property2" };
With EF5 on .NET 4.5 you can do this:
var entry = context.Entry(obj);
entry.State = EntityState.Modified;
foreach (var name in excluded)
{
entry.Property(name).IsModified = false;
}
This uses a new feature of EF5 on .NET 4.5 which allows a property to be set as not modified even after it has been previously set to modified.
When using EF 4.3.1 or EF5 on .NET 4 you can do this instead:
var entry = context.Entry(obj);
foreach (var name in entry.CurrentValues.PropertyNames.Except(excluded))
{
entry.Property(name).IsModified = true;
}
You can't define such an exception. You can however mark single properties as modified:
context.Entry(obj).Property(o => o.Property3).IsModified = true;
context.Entry(obj).Property(o => o.Property4).IsModified = true;
// etc.
Note that setting IsModified to false is not supported once you have marked the state of the whole entity to Modified.
For your purpose I would actually prefer to load the entity from the database and then update it using normal change tracking:
var objInDB = context.Objects.Single(o => o.Id == obj.Id);
obj.Property1 = objInDB.Property1;
obj.Property2 = objInDB.Property2;
context.Entry(objInDB).CurrentValues.SetValues(obj);
context.SaveChanges();
Note that only changed properties will be saved by default by Automatic Detect changes.
See EF 6 and EF Core articles
This question was already nicely answered, but I wanted to provide an extension method for anyone who would like to use it.
This code was developed for EF 4.3.1
//You will need to import/use these namespaces
using System.Data.Entity;
using System.Data.Entity.Infrastructure;
//Update an entity object's specified columns, comma separated
//This method assumes you already have a context open/initialized
public static void Update<T>(this DbContext context, T entityObject, params string[] properties) where T : class
{
context.Set<T>().Attach(entityObject);
var entry = context.Entry(entityObject);
foreach(string name in properties)
entry.Property(name).IsModified = true;
context.SaveChanges();
}
Usage Example
using (FooEntities context = new FooEntities())
{
FooEntity ef = new FooEntity();
//For argument's sake say this entity has 4 columns:
// FooID (PK), BarID (FK), Name, Age, CreatedBy, CreatedOn
//Mock changes
ef.FooID = 1;
ef.Name = "Billy";
ef.Age = 85;
context.Update<FooEntity>(ef, "Name", "Age"); //I only want to update Name and Age
}
This is an update that works for .net CORE and maybe can help someone who needs a generic solucion and wants to exclude some properties base on different conditions.
I'm using reflection to iterate through the properties and update base on its property value, in this case, as example, i'm excluding the null properties.
public virtual TEntity Update(TEntity entity)
{
dbSet.Attach(entity);
dbContext.Entry(entity).State = EntityState.Modified;
var entry = dbContext.Entry(entity);
Type type = typeof(TEntity);
PropertyInfo[] properties = type.GetProperties();
foreach (PropertyInfo property in properties)
{
if (property.GetValue(entity, null) == null)
{
entry.Property(property.Name).IsModified = false;
}
}
dbContext.SaveChanges();
return entity;
}
The answers above (most of them) use DbContext. For those who is using ObjectContext these solutions arent accessible.
Here is solution for ObjectContext strictly (EF5 .NET 4.5):
ctx.AddObject("ENTITYNAME", item);
ctx.ObjectStateManager.ChangeObjectState(item, EntityState.Modified);
var entry = ctx.ObjectStateManager.GetObjectStateEntry(item);
entry.RejectPropertyChanges("PROPERTY_TO_EXCLUDE");
I'm using EF4. I'm adding a series of new entities from a list of DTOs, and I'm not saving changes until after all of them are added. I'm wanting to set the IDs of the DTOs to what the new entities' IDs are. How on earth do I do this? Does EF provide a mechanism for this?
With a single entity I would do this:
public void InsertMyDto(MyDto a_dto)
{
var newEntity = new MyEntity
{
Name = a_dto.Name,
Type = a_dto.Type.ToString(),
Price = a_dto.Price
};
_dataContext.MyEntities.AddObject(newEntity);
_dataContext.SaveChanges();
a_dto.ID = newEntity.ID;
}
This works fine, but what do I do in this case?
public void InsertMyDtos(IEnumerable<MyDto> a_dtos)
{
foreach (var myDto in a_dtos)
{
var newEntity = new MyEntity
{
Name = myDto.Name,
Type = myDto.Type.ToString(),
Price = myDto.Price
};
// Does some validation logic against the database that might fail.
_dataContext.MyEntities.AddObject(newEntity);
}
_dataContext.SaveChanges();
// ???
}
I want to save all at once, because I have validation work (not shown above) that is done against the database and fails before it gets to SaveChanges, and if it fails I want it to fail as a whole transaction (i.e. rollback).
I don't think that EF can help you here. It even can't help you for a single instance which forces you to write a_dto.ID = newEntity.ID. The counterpart of this code for multiple entites is to keep track of the pairs of dtos and new entities:
public void InsertMyDtos(IEnumerable<MyDto> a_dtos)
{
Dictionary<MyDto, MyEntity> dict = new Dictionary<MyDto, MyEntity>();
foreach (var myDto in a_dtos)
{
var newEntity = new MyEntity
{
Name = myDto.Name,
Type = myDto.Type.ToString(),
Price = myDto.Price
};
dict.Add(myDto, newEntity);
// Does some validation logic against the database that might fail.
_dataContext.MyEntities.AddObject(newEntity);
}
_dataContext.SaveChanges();
foreach (var item in dict)
item.Key.ID = item.Value.ID; // Key is MyDto, Value is MyEntity
}
I transfer data between the entity framework and the business layer and user layer by using Data Transfer Objects. I do have some doubt, if I retrieve an object which is converted to a DTO, how do I update the correct object in the entity framework and not just insert a duplicate?
The following code will update an EF 4 entity that has been created as a controller parameter in MVC from a strongly typed view:
It seems the trick is to use the ObjectStateManager to change the state from Added to Modified once the entity has been added to the context.
MyEntities db = new MyEntities();
db.Product.AddObject(product);
db.ObjectStateManager.ChangeObjectState(product, System.Data.EntityState.Modified);
return db.SaveChanges() > 0;
As per #Sean Mills comment if you are using EF5 use:
((IObjectContextAdapter) db).ObjectContext.ObjectStateManager.ChangeObjectState(entity, System.Data.EntityState.Added);
an old question, but just in case someone needs a code solution:
http://www.mikesdotnetting.com/Article/110/ASP.NET-MVC-Entity-Framework-Modifying-One-to-Many-and-Many-to-Many-Relationships
Example:
public void EditArticle(
Article article, string articleTypeId, string[] categoryId)
{
var id = 0;
Article art = de.ArticleSet
.Include("ArticleTypes")
.Include("Categories")
.Where(a => a.ArticleID == article.ArticleID)
.First();
var count = art.Categories.Count;
for (var i = 0; i < count; i++)
{
art.Categories.Remove(art.Categories.ElementAt(i));
count--;
}
foreach (var c in categoryId)
{
id = int.Parse(c);
Category category = de.CategorySet
.Where(ct => ct.CategoryID == id).First();
art.Categories.Add(category);
}
art.Headline = article.Headline;
art.Abstract = article.Abstract;
art.Maintext = article.Maintext;
art.DateAmended = DateTime.Now;
art.ArticleTypesReference.EntityKey = new EntityKey(
"DotnettingEntities.ArticleTypeSet",
"ArticleTypeID",
int.Parse(articleTypeId)
);
de.SaveChanges();
}
//I am replacing player :)
public ActionResult ProductEdit(string Id, Product product)
{
int IdInt = DecyrptParameter(Id);
MyEntities db = new MyEntities();
var productToDetach = db.Products.FirstOrDefault(p=> p.Id == IdInt);
if (product == null)
throw new Exception("Product already deleted"); //I check if exists, maybe additional check if authorised to edit
db.Detach(productToDetach);
db.AttachTo("Products", product);
db.ObjectStateManager.ChangeObjectState(product, System.Data.EntityState.Modified);
db.SaveChanges();
ViewData["Result"] = 1; // successful result
return View();
}
You would need to include a primary or alternate key in the DTO, then match that key back to the correct EF entity upon update.
This should work for EF 5: https://stackoverflow.com/a/11749716/540802:
db.Entry(product).State = EntityState.Modified;