Is there a way to use SetValues() when creating an entity framework object.
I have a class with same field definitions as my entity framework class and found this explanation of an easier way to update ef records using the SetValues function.
https://researchaholic.com/2013/02/06/entity-framework-5-easier-way-to-update-record/
The question I have is this: Is there a similar way to create new ef records without specifying every field like this:
var newItm = new Import.EntityClasses.ImportSiteList {
SiteId = ssItm.SiteId,
OrganizationId = ssItm.OrganizationId,
TimeZoneId = ssItm.TimeZoneId
};
tbl.Add(newItm);
This is how you can do
var newItm = new Import.EntityClasses.ImportSiteList();
context.Entry(newItm).State = EntityState.Added;
context.Entry(newItm).CurrentValues.SetValues(ssItm);
context.SaveChanges();
Hope it helps.
Related
I have the following piece of code
private void DoAddPropertyType()
{
var ctx = Globals.DbContext;
var propType = new PropertyType()
{
ID = Guid.NewGuid(),
Name = "NewType",
Description = "New Property Type",
ModifiedDate = DateTime.Now
};
ctx.AddToPropertyTypes(propType);
PropertyTypes.Add(propType);
}
Globals.DbContext provides a static reference to the objectcontext initiated on startup. For some reason the ctx.AddToPropertyTypes(propType); bit does not add the entity to the context. If I breakpoint after that line and browse the ctx.PropertyTypes entity set it is not there. Any ideas?
EDIT 1:
If I add a ctx.SaveChanges() after the ctx.AddToPropertyTypes(propType) and step the actual adding appears to happen only once SaveChanges execute. This however does not suit my requirements as I want to first validate objects prior to saving and wanted to iterate through the entities in the entity set. Does any one know of an alternative approach?
So that is the point of your issue. ctx.PropertyTypes is not a real collection - it is entrance to the database and your "browsing" actually executes query to the database where your new object was not yet stored. If you want to find a new object added to the context without saving it first you must search the object inside the ObjectStateManager:
var entity = ctx.ObjectStateManager
.GetObjectStateEntries(EntityState.Added)
.Where(e => !e.IsRelationship)
.Select(e => e.Entity)
.OfType<PropertyType>()
.SingleOrDefault(p => p.ID == ...);
I have this entity, want to update using entityframework
EmployeeModel employee = new EmployeeModel
{
Id = 1000, //This one must
FirstName = modifiedValue,
Email = modifiedValue,
LastName = originalValue,
Phone = originalValue
};
Code to update
_db.ObjectStateManager.ChangeObjectState(employee, EntityState.Modified);
_db.SaveChanges();
This is the SQL statement got once updated
Update Employee set Id=1138,FirstName='modifiedValue',Email='modifiedValue',LastName= 'OriginalValue',phone='originalValue' where Id=1138
But I am expecting this
Update Employee set FirstName='modifiedValue', Email='modifiedValue' where Id=1138.
I dont know what I am missing here. Please let me know.
This problem is common when dealing with DTOs. An employee entity is fetched from the database, mapped to a DTO and sent over the wire. The client then modifies this DTO and sends it back to the server.
When you touch (set) a property on an EF entity, EF will assume that the value has been changed. Even if the old value and the new value are exactly the same.
The same problem occurs when you map the DTO to a new Entity and attach it to EF and updating its status to 'Modified'.
Using AutoMapper:
// This will result in the full update statement
var employee = AutoMapper.Mapper.Map<EmployeeDto, Employee>(dto);
// This will result in a smaller update statement (only actual changes)
var employee = dbContext.Employees.Find(dto.Id);
AutoMapper.Mapper.Map(dto, employee);
Or, manually (I would avoid doing this, but just for the sake of completeness):
// This will result in a smaller update statement (only actual changes)
var employee = dbContext.Employees.Find(dto.Id);
if (employee.Email != dto.Email )
employee.Email = dto.Email;
There are probably some other ways for dealing with this problem... but using AutoMapper together with Entity Framework correctly is definitely one of the easiest ways.
This is the solution I got
var entity = _db.CreateObjectSet<Employee>();
entity.Detach(employee);
entity.Attach(employee);
foreach (string modifiedPro in employeeModel.ModifiedProperties){
_db.ObjectStateManager.GetObjectStateEntry(employee).SetModifiedProperty(modifiedPro);}
_db.SaveChanges();
Only modified values in the sql update statement
Update Employee set FirstName='modifiedValue', Email='modifiedValue' where Id=1138.
If anybody knows better answer than this, Please post your suggestions
You can try this way
public update(Person model)
{
// Here model is model return from form on post
var oldobj = db.Person.where(x=>x.ID = model.ID).SingleOrDefault();
var UpdatedObj = (Person) Entity.CheckUpdateObject(oldobj, model);
db.Entry(oldobj).CurrentValues.SetValues(UpdatedObj);
}
public static object CheckUpdateObject(object originalObj, object updateObj)
{
foreach (var property in updateObj.GetType().GetProperties())
{
if (property.GetValue(updateObj, null) == null)
{
property.SetValue(updateObj,originalObj.GetType().GetProperty(property.Name)
.GetValue(originalObj, null));
}
}
return updateObj;
}
I'm working on a MVC3 application and i'm using the Entity Framework linked to an Oracle database (11G R2).
I'm encountering an issue when i'm trying to use a single object context inside a TransactionScope.
Here is the code :
using (TransactionScope scope = new TransactionScope())
{
using (Entities context = new Entities())
{
// Right insert
T_RIGRIGHT entity1 = new T_RIGRIGHT()
{
RIGCODE = "test1",
RIGINSERTLOGIN = "aco",
RIGINSERTDATE = DateTime.Now,
RIGUPDATELOGIN = "aco",
RIGUPDATEDATE = DateTime.Now
};
context.AddToT_RIGRIGHT(entity1);
context.SaveChanges();
// Right/Profile insert
T_RIPRIGHTPROFILE entity2 = new T_RIPRIGHTPROFILE()
{
PROID = 3,
RIGID = entity1.RIGID,
RIPINSERTLOGIN = "aco",
RIPINSERTDATE = DateTime.Now,
RIPUPDATELOGIN = "aco",
RIPUPDATEDATE = DateTime.Now
};
context.AddToT_RIPRIGHTPROFILE(entity2);
context.SaveChanges(); // SaveChanges fails due to the FK constraint on table
}
scope.Complete();
}
Let me explain the code...
First I create an entity called entity1 as a T_RIGRIGHT element.
The I instanciate a T_RIPRIGHTPROFILE element that uses the id of the T_RIGRIGHT element created before.
The execution fails on the second context.SaveChanges() and the exception concerns the Foreign Key constraint on the table T_RIPRIGHTPROFILE (requires a T_RIGRIGHT).
Hope my explanations are clear enough
Is there any way to make it works ?
P.S. : I apologize for my english as it's not my native language.
You are trying to assign the FK entity1.RIGID of an entity that has not been committed to the DB:
RIGID = entity1.RIGID,
If you look at entity1 closely you will see that RIGID is 0 by default - instead you should set the navigation property representing the FK relationship:
RIG = entity1,
This will enable EF to properly relate these entities, for this entity1 does not have to be committed to the DB yet, so you do not even need the extra SaveChanges() call.
Also in your scenario you do not need a TransactionScope - EF uses a transaction internally already in SaveChanges() - based on the suggested changes you only need one SaveChanges() call and hence no outer transaction scope is needed.
Hi I use C# and EF 4.
I have two Entities CmsContent and CmsJob.
CmsJob has a navigational property to CmsContent.
I need add a CmsContent Object to CmsJob using the navigational property.
My code run with no error but I cannot persist the new entry om DataBase.
Could you tell me what I'm doing wrong?
Please provide me an example of code. Thanks for your support!
using (CmsConnectionStringEntityDataModel context = new CmsConnectionStringEntityDataModel())
{
CmsContent myContent = context.CmsContents.FirstOrDefault(x => x.ContentId == contentId);
CmsJob myJob = context.CmsJobs.FirstOrDefault(x => x.JobId == jobId);
myJob.CmsContents.Add(myContent);
}
Based on comments under #Hasan's answer you have incorrectly defined database. Your Job and Content are in many-to-many relation so you have junction table called CmsJobsContents but this table is missing primary key. Because of that it is read-only for EF and you cannot create new relations in your application. You must go to your database and mark both FKs in the CmsJobsContents as primary keys. After that update your model from database and you should be able to save changes.
That's because you haven't saved changes. Try this:
using (CmsConnectionStringEntityDataModel context = new CmsConnectionStringEntityDataModel())
{
CmsContent myContent = context.CmsContents.FirstOrDefault(x => x.ContentId == contentId);
CmsJob myJob = context.CmsJobs.FirstOrDefault(x => x.JobId == jobId);
myJob.CmsContents.Add(myContent);
context.SaveChanges();
}
I just spent the last 3-4 hours trying to retrieve a foreign key value using linq to entities and a stored procedure. Any advice is much appreciated.
public JsonResult GetEvents(double? start, double? end)
{
AnoEntities _dbAno = new AnoEntities();
var events = _dbAno.Events_GetByDateRange(fromDate, toDate);
var eventList = from e in events
select new
{
id = e.id,
title = e.title,
className = e.event_types.type.ToString()
};
return Json(eventList.ToArray());
}
type_id is the foreign key value that i'm trying to reach. I can't get it so appear in the entity data model and I can't seem to get to it. e.event_types and e.event_typesReference are both null so things like e.event_typesReference.EntityKey.EntityKeyValues.First().Value.ToString() aren't working.
Thanks!
I don't see any .Include methods or Load methods on even_types and I'm assuming your returning IEnumerable from your _dbAno.Events_GetByDateRange(fromDate, toDate). Like Craig pointed out in the comments if your return type of GetByDateRange is IQueryable you'd be projecting and EF should eager load for you.
Just a reminder that implicit lazy loading isn't supported out of the box in Entity Framework 1.0. You'll need to manually load the event_types with Load() or use the Include method on ObjectQuery.