Develop Reference

EF7 - Properties object from entity class are not being filled

Good night!
I am playing with EF7 to learn about it.
I've created the next classes:
public class Lawsuit
{
/// <summary>
/// Lawsuit identificator.
/// </summary>
public Guid LawsuitId { get; set; }
/// <summary>
/// Date time asigned where lawsuit was created.
/// </summary>
public DateTime DateTimeCreated { get; set; }
/// <summary>
/// First part envolved signature object.
/// </summary>
public virtual Signature? FirstPartyEnvolved { get; set; }
/// <summary>
/// First part envolved signature object.
/// </summary>
public virtual Signature? SecondPartyEnvolved { get; set; }
/// <summary>
/// Winner position indicator
/// </summary>
public WinnerPosition? WinnerPosition { get; set; }
}
public class Signature
{
/// <summary>
/// Id from signature.
/// </summary>
public Guid Id { get; set; }
/// <summary>
/// String which saves text received from contract signatures.
/// </summary>
public string? Signatures { get; set; }
}
At insert, the data is created correctly at database (SQL Server), but when I try to obtain the data, FirstPartyEnvolved and SecondPartyEnvolved attributes are empty.
Example of response:
[
{
"lawsuitId": "6ece06da-d5f9-40e7-a7a3-2816618e7869",
"dateTimeCreated": "2022-12-12T22:05:24.4717517",
"firstPartyEnvolved": null,
"secondPartyEnvolved": null,
"winnerPosition": 1
}
]
I was checking if the DTO object was not parsing well the data but the problem seems to be at the Entity object
public Task Handle()
{
var Lawsuites_repo = LawsuitRepository.GetAllLawsuit();
var Lawsuites = Lawsuites_repo.Select(x =>
new LawsuitDTO
{
LawsuitId = x.LawsuitId,
DateTimeCreated = x.DateTimeCreated,
WinnerPosition = x.WinnerPosition ?? 0,
FirstPartyEnvolved = x.FirstPartyEnvolved,
SecondPartyEnvolved = x.SecondPartyEnvolved
});
GetAllLawsuitsOutputPort.Handle(Lawsuites);
return Task.CompletedTask;
}
I've tried to changed the Signatures objects for GUID and I am receiving well this data. Seems a problem parsing the object from the EF context to the Entity class.

You haven't detailed what is in your GetAllLawsuit() method, but EF does not eager load related entities by default, so you are likely just ToList()'ing the content, then the collection will be loaded from the database with null references for the Signatures
If you remove the call to GetAllLawsuit() and use the Select projection directly from the DbContext, then it will work.
You can also force EF to eager load your related entities by using the Include extension method in your GetAllLawsuit method.

How to remove (via linq) duplicates from a List of objects

My main object, has a property which is a List of tags
[SharedCosmosCollection("shared")]
public class GlobalPageTemplate : ISharedCosmosEntity
{
/// <summary>
/// Id
/// </summary>
[JsonProperty("Id")]
public string Id { get; set; }
/// <summary>
/// Cosmos Entity name
/// </summary>
[CosmosPartitionKey]
public string CosmosEntityName { get; set; }
/// <summary>
/// Page name
/// </summary>
public string ExtractedPageName { get; set; }
/// <summary>
/// Site collection Template Name
/// </summary>
public string ExtractedSitecollectionTemplateName { get; set; }
/// <summary>
/// GlobalDesignTenantId
/// </summary>
public string ExtractedGlobalDesignTenantId { get; set; }
/// <summary>
/// Global design tenant site collection url
/// </summary>
public string ExtractedGlobalDesigntenantSiteCollectionUrl { get; set; }
/// <summary>
/// Page template picture Url
/// </summary>
public string PageTemplatePictureUrl { get; set; }
/// <summary>
/// Base64 image of the page template
/// </summary>
public string Base64Image { get; set; }
/// <summary>
/// Name of the template
/// </summary>
public string PageTemplateName { get; set; }
/// <summary>
/// Page sections
/// </summary>
public List<Section> Sections { get; set; }
/// <summary>
/// Tags
/// </summary>
public List<Tag> Tags { get; set; }
}
Tag object is here:
public class Tag : ISharedCosmosEntity
{
/// <summary>
/// Id
/// </summary>
[JsonProperty("Id")]
public string Id { get; set; }
/// <summary>
/// Tag name
/// </summary>
public string TagName { get; set; }
/// <summary>
/// cosmos entity name
/// </summary>
[CosmosPartitionKey]
public string CosmosEntityName { get; set; }
}
In my WebAPI, from the frontend, I might get duplicate tags,
how do I remove them and leave a clean list of tags before saving?

Can I suggest altering your data structure that stores your tags to a HashSet? If so, you can then do something like this.
A HashSet is an unordered collection of unique elements. It is generally used when we want to prevent duplicate elements from being placed in a collection. The performance of the HashSet is much better in comparison to the list.
Essentially, you supply a custom IEqualityComparer to your HashSet on initialization.
public class TagComparer : IEqualityComparer<Tag>
{
public bool Equals(Tag x, Tag y)
{
return x.Id.Equals(y.Id, StringComparison.InvariantCultureIgnoreCase);
}
public int GetHashCode(Tag obj)
{
return obj.Id.GetHashCode();
}
}
And then you can do
HashSet<Tag> Tags = new HashSet<Tag>(new TagComparer());
In general, I always try to use data structures that make sense for the problem at hand. If you know you'll always want this collection to have unique elements, then I suggest you use a HashSet.
If you can't use a HashSet and you want to stick with a list, you can use linq's Distinct method on your Tags list and pass in the TagComparer object from above .
List<Tag> DistinctTagList = Tags.Distict(new TagComparer())

Not exactly an answer to your question (the other answers are all valid solutions for that), but if for some reason you're looking to actually extract your duplicate objects, such as for debugging, error processing, whatever, I wanted to offer the below.
var duplicates = someList
.GroupBy(r => r.Id)
.Where(g => g.Count() > 1)
.ToList();
Then you have a slightly different way to manage your list from pure distinct
someList = someList.Except(duplicates).ToList();
Which is then a list of keys which had no duplicates.

what you are looking for is probably the distict method:
https://learn.microsoft.com/en-us/dotnet/api/system.linq.enumerable.distinct?view=netframework-4.8
for that you would also need to write an IEqualityComparer, which can simply compare by property https://learn.microsoft.com/en-us/dotnet/api/system.collections.generic.iequalitycomparer-1?view=netframework-4.8
Then you could call it on your Enumerable:
var distinctTags = Tags.Distict(new TagEqualityComparer)
And the equalityComparer:
class TagEqualityComparer : IEqualityComparer<Tag>
{
public bool Equals(Tag t1, Tag t2)
{
if (t2 == null && t1 == null)
return true;
else if (t1 == null || t2 == null)
return false;
else if(t1.Id == t2.Id)
return true;
else
return false;
}
public int GetHashCode(Tag t)
{
// any custom hashingfunction here
}
}

Using only linq you can do this:
If tags have unique ids:
tags.GroupBy(x => x.Id).Select(x => x.First()).ToList();
If you need to compare all columns:
tags.GroupBy(x => new {x.Id, x.TagName, x.CosmosEntityName}).Select(x => x.First()).ToList();

EF tracking changes in database

im using Entity Framework6 in my solution, and now i need to track changes in database but cant figure out how to do it.
Is there a way to track changes in database using Entity Framwork?
update:
I've found this solution, its using SqlDependency in the way that allows to use it With Entity framework.
http://www.codeproject.com/Articles/233770/AutoRefresh-Entity-Framework-data-using-SQL-Server

I've found this solution, its using SqlDependency in the way that allows to use it With Entity framework.
http://www.codeproject.com/Articles/233770/AutoRefresh-Entity-Framework-data-using-SQL-Server

You can overwrite the SaveChanges() method to track the changes. Here's some example out of one of our applications:
public override int SaveChanges()
{
ChangeTracker.DetectChanges();
var entries = ChangeTracker.Entries<IAuditable>();
if (entries != null)
{
foreach (DbEntityEntry<IAuditable> entry in entries)
{
switch (entry.State)
{
case EntityState.Added:
entry.Entity.SystemFields = new SystemFields
{
SysActivityCode = ActivityCode,
SysCreationUser = UserId,
SysCreationDate = DateTime.UtcNow
};
break;
case EntityState.Modified:
entry.Entity.SystemFields.SysModificationDate = DateTime.UtcNow;
entry.Entity.SystemFields.SysModificationUser = UserId;
entry.Entity.SystemFields.SysActivityCode = ActivityCode;
break;
}
}
}
return base.SaveChanges();
}
where SystemFields is a ComplexType added to all entries which implement the IAuditable interface:
public interface IAuditable
{
/// <summary>
/// System fields who contain change and status information
/// </summary>
SystemFields SystemFields { get; set; }
}
[ComplexType]
public class SystemFields
{
/// <summary>
/// When has this entry be created
/// </summary>
[Required]
public DateTime SysCreationDate { get; set; }
/// <summary>
/// Who has created the entry
/// </summary>
[Required]
public string SysCreationUser { get; set; }
/// <summary>
/// When has this entry been modified
/// </summary>
public DateTime? SysModificationDate { get; set; }
/// <summary>
/// Who has updated the entry
/// </summary>
[CanBeNull]
public string SysModificationUser { get; set; }
/// <summary>
/// Which activity has created/changed this entry
/// </summary>
[Required]
[StringLength(32)]
public string SysActivityCode { get; set; }
}

Adding Comments button against list of wcf service

I have call a list of phone records in wcf service. Now i need to add comments & feedback against all records, in such a way that user clicks the notes button and then enter the comments and feedback aaisnt a specific record.
Here is my class FOR notes
public class CallNote
{
public int Id { get; set; }
///<Summary>
///
///</Summary>
public string Comments { get; set; }
///<Summary>
///
///</Summary>
///
public string FeedBack { get; set; }
///<Summary>
///
///</Summary>
///
public string Login { get; set; }
}
Class for callhistory
public class CallHistory
{
/// <summary>
///
/// </summary>
///
public int CallId { get; set; }
/// <summary>
///
/// </summary>
///
public string Login { get; set; }
/// <summary>
///
/// </summary>
public string FirstName { get; set; }
/// <summary>
///
/// </summary>
public string LastName { get; set; }
/// <summary>
///
/// </summary>
public string Email { get; set; }
/// <summary>
///
/// </summary>
public string Country { get; set; }
/// <summary>
///
/// </summary>
public string Phone { get; set; }
/// <summary>
///
/// </summary>
public string DialedNumber { get; set; }
/// <summary>
///
/// </summary>
public string CallStart { get; set; }
/// <summary>
///
/// </summary>
public string CallEnd { get; set; }
/// <summary>
///
/// </summary>
public string TariffDescription { get; set; }
/// <summary>
///
/// </summary>
}
and here is my controller
public ActionResult CreateNote()
{
var result = Manager.GetUsersWhoHaveConsumedFreeCredit();
JavaScriptSerializer serializer = new JavaScriptSerializer();
var callHistory = serializer.Deserialize<List<CallHistory>>(result);
return View(callHistory.ToPagedList(1, Settings.PagingSize));
}
[HttpPost]
public ActionResult CreateNote(CallNote callnote)
{
CallNote_Db db = new CallNote_Db();
if (ModelState.IsValid)
{
db.callnote.Add(callnote);
db.SaveChanges();
return RedirectToAction("CallHistory");
}
return PartialView("CallHistory", callnote);
}
public ActionResult UsersWhoHaveConsumedFreeCredit(int Id = 1)
{
var result = Manager.GetUsersWhoHaveConsumedFreeCredit(); ;
JavaScriptSerializer serializer = new JavaScriptSerializer();
var callHistory = serializer.Deserialize<List<CallHistory>>(result);
CallNote callNote = new Models.CallNote();
CallHistoryFilter callHistoryFilter = new Models.CallHistoryFilter();
MyYelloAdminEntities db = new Models.MyYelloAdminEntities();
{
callHistoryFilter.Countries = db.Countries.ToList();
callHistoryFilter.Countries.Insert(0, new Country { Title = "All", Prefix = "-1" });
var model = new UsersWhoHaveConsumedFreeCredit
{
CallHistory = callHistory.ToPagedList(Id, Settings.PagingSize),
CallHistoryFilter = callHistoryFilter
};
return View(model);
}
}
How i can add comments against each record.

If you want to combine two different WCF data contracts for your UI/display convenience,
then you can create a view model in your MVC project that is composed of these two datacontracts.
And once after you fetch WCF contracts to your MVC app then crate a datamapper(perhaps by using Automapper or a mapper of your choice) between WCF to your ViewModel and reverse the process while pushing data from UI back to WCF service.
Update based on your comments:
Please take a look at AutoMapper, it is a mapping tool to copy your property data from one type of entity to other type based on the mapping strategy you defined.
If you need to maintain comments/feedback at the currently logged in user then, you can track that on server and you need to only get the new comments from UI to controller and prepare the Model to save accordingly.
If you need to maintain comments/feedback at the respective user(the registered user who is providing the comments/feedback against your content) level, then you can maintain a hidden field on view and then you should post the userid and comments back to controller and save them.

How do I compare two instances of a ViewModel for value equality in C#

So I have a ViewModel for searching my database. I intend to refactor away the result set collection. I don't think it belongs in this ViewModel. All I want to do is when the user submits the page is compare the ViewModel passed to my Controller Action with the ViewModel stored in TempData. So I can tell if it is the SameSearch.
So how could that be done? considering I have many many many properties in my viewModel I'd prefer not to compare one by one. And using Json.Encode to serialize them and compare seems "hacky" to me.
Also, if I do have to compare one by one. Should that be done by overriding .Equals()
controller action Search()
public ActionResult Search(SearchViewModel model)
{
SearchViewModel savedSearch = null;
if (Request["submit"].Equals("reset",StringComparison.OrdinalIgnoreCase))
{
TempData.Remove("filter");
model = new SearchViewModel();
}
else if (TempData.ContainsKey("filter"))
{
savedSearch = (SearchViewModel)Convert.ChangeType(TempData["filter"], typeof(SearchViewModel));
}
var currentmodel = System.Web.Helpers.Json.Encode(model);
var savedmodel = System.Web.Helpers.Json.Encode(savedSearch);
if (savedSearch == null)
{
model.NewSearch = true;
}
//The search hasn't changed.
if(currentmodel == savedmodel)
{
model.isSameSearch = true;
}
else
{
model.isSameSearch = false;
}
//do more stuff
//return view
}
ViewModel SearchViewModel
public class SearchViewModel
{
public SearchViewModel()
{
Page = 1;
BuildingSearch = new SearchBuildingViewModel();
ParcelSearch = new SearchParcelViewModel();
SalesSearch = new SearchSalesViewModel();
PropertyFeatureSearch = new SearchPropertyFeaturesViewModel();
ValuesSearch = new SearchValuesViewModel();
}
/// <summary>
/// Gets or sets a value indicating whether use advanced search.
/// </summary>
public bool UseAdvancedSearch { get; set; }
public bool NewSearch { get; set; }
public bool isSameSearch { get; set; }
/// <summary>
/// Gets or sets the page.
/// </summary>
[HiddenInput]
[ScaffoldColumn(false)]
public int Page { get; set; }
[HiddenInput]
[ScaffoldColumn(false)]
public string SortOption { get; set; }
#region Search View Models
/// <summary>
/// Gets or sets the building search.
/// </summary>
public SearchBuildingViewModel BuildingSearch { get; set; }
/// <summary>
/// Gets or sets the parcel search.
/// </summary>
public SearchParcelViewModel ParcelSearch { get; set; }
/// <summary>
/// Gets or sets the property feature search.
/// </summary>
public SearchPropertyFeaturesViewModel PropertyFeatureSearch { get; set; }
/// <summary>
/// Gets or sets the sales search.
/// </summary>
public SearchSalesViewModel SalesSearch { get; set; }
/// <summary>
/// Gets or sets the values search.
/// </summary>
public SearchValuesViewModel ValuesSearch { get; set; }
#endregion
/// <summary>
/// Gets or sets the search results.
/// </summary>
[ScaffoldColumn(false)]
public IPagination<ParcelResultItemViewModel> SearchResults { get; set; }
}

Implement IEquatable<T> in your ViewModel where T is the ViewModel class name, and create your own Equals method logic:
public bool Equals(ViewModel other)
{
//compare properties, etc here
}
And override GetHashCode():
public override int GetHashCode()
{
//you custom hash code algorithm
}

Consider using http://comparenetobjects.codeplex.com/ which will do a deep compare of objects. You can even use NuGet to get it: http://www.nuget.org/packages/CompareNETObjects