I need keep the same original Id (GUID) after save data because is a replication job. (SQL -> SQL remote). Then, the model can not be changed. After SaveChanges() EF insert a new random Guid as Id, then this changes my original object, and do not want that. A compact sample:
class EFInsertTest
{
public void InsertTest()
{
var id = new Guid("D75C887D-BF25-E611-943B-080027BA87E8"); // dummy
var entity = new Something { Id = id, Name = "ELENOR" };
using (var db = new SomethingContext())
{
db.Things.Add(entity);
db.SaveChanges();
// TEST
if (db.Things.Find(id) != null)
{
Console.WriteLine($"Great! Expected behavior");
}
else
{// run this:
Console.WriteLine($"Failed! Id has another value");
}
Console.ReadKey();
// SQL hard code (works fine)
db.Database.ExecuteSqlCommand($"INSERT INTO [Something] VALUES('{id}', '{entity.Name}')");
db.SaveChanges();
// TEST
if (db.Things.Find(id) != null)
{
Console.WriteLine($"Great! Expected behavior");
}
else
{
Console.WriteLine($"Failed! Id has another value");
}
Console.ReadKey();
}
}
}
public class SomethingContext : DbContext
{
public virtual DbSet<Something> Things { get; set; }
}
public class Something
{
[Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public Guid Id { get; set; }
public string Name { get; set; }
}
Related
I have a Kalem Entity with a collection of DigerKalemMaliyetleri property, which is a collection of MaliyetBirimi objects. DigerKalemMaliyetleri is of JSON type and stored at the same table as a JSON column.
public class Kalem
{
public int Id { get; set; }
[Column(TypeName = "json")]
public ICollection<MaliyetBirimi> DigerKalemMaliyetleri { get; set; }
}
public class MaliyetBirimi
{
public int? DovizCinsi { get; set; }
public decimal? Maliyet { get; set; }
}
When I try to update entity with only DigerKalemMaliyetleri property changed:
DataContext.Entry<Kalem>(first).CurrentValues.SetValues(second);
SQL Update command isn't executed and database record is not updated.
How could I update the entity without explicitly setting DigerKalemMaliyetleri property?
Regards
I had the same problem, you cann't actually use SetValues to update navigation property, you nead instead use DataContext.Update(YourNewObj) and then DataContext.SaveChanges();, or if you want to use SetValues approach, you need:
-Get the exist entry
Kalem existObj = DataContext.Kalems.Find(YourNewObj.Id);
-Loop in navigations of updating entry and the existing one to set the values of updating entry:
foreach(var navObj in DataContext.Entry(YourNewObj).Navigations)
{
foreach(var navExist in DatatContext.Entry(existObj).Navigations)
{
if(navObj.Metadata.Name == navExist.MetaData.Name)
navExist.CurrentValue = navObj.CurrentValue;
}
}
-Update also changes of direct properties:
DataContext.Entry(existObj).CurrentValues.SetValues(YourNewObj);
-Save your Updating:
DataContext.SaveChanges();
You can also check if you need to load your Navigations before going in foreach loop, otherwise you will get an error.
Please if you see beter scenario, correct me.
It's hard to know exactly what you're doing without a complete code sample. Note also that you're trying to set all properties of first from second, including e.g. the Id, which is probably not what you want.
Here's a complete code sample which works for me:
await using (var ctx = new BlogContext())
{
await ctx.Database.EnsureDeletedAsync();
await ctx.Database.EnsureCreatedAsync();
ctx.Kalem.Add(new()
{
DigerKalemMaliyetleri = new List<MaliyetBirimi>()
{
new() { DovizCinsi = 1, Maliyet = 2 }
}
});
await ctx.SaveChangesAsync();
}
await using (var ctx = new BlogContext())
{
var first = ctx.Kalem.Find(1);
var second = new Kalem
{
DigerKalemMaliyetleri = new List<MaliyetBirimi>()
{
new() { DovizCinsi = 3, Maliyet = 4 }
}
};
ctx.Entry(first).Property(k => k.DigerKalemMaliyetleri).CurrentValue = second.DigerKalemMaliyetleri;
await ctx.SaveChangesAsync();
}
public class BlogContext : DbContext
{
public DbSet<Kalem> Kalem { get; set; }
static ILoggerFactory ContextLoggerFactory
=> LoggerFactory.Create(b => b.AddConsole().AddFilter("", LogLevel.Information));
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
=> optionsBuilder
.UseNpgsql(#"Host=localhost;Username=test;Password=test")
.EnableSensitiveDataLogging()
.UseLoggerFactory(ContextLoggerFactory);
}
public class Kalem
{
public int Id { get; set; }
[Column(TypeName = "json")]
public ICollection<MaliyetBirimi> DigerKalemMaliyetleri { get; set; }
}
public class MaliyetBirimi
{
public int? DovizCinsi { get; set; }
public decimal? Maliyet { get; set; }
}
I'm trying to get the Audit:NET EntityFramework.Core extension to write an AuditLog entry per changed property.
For this purpose I've overidden the EntityFrameworkDataProvider.InsertEvent with a custom DataProvider.
The problem is, using DbContextHelper.Core.CreateAuditEvent to create a new EntityFrameworkEvent returns null.
The reason seems to be, at this point in the code execution DbContextHelper.GetModifiedEntries determines all EF Entries have State.Unmodified, even if they are clearly included in the EventEntry changes.
I'm trying to circumvent CreateAuditEvent by manually creating the contents is impossible due to private/internal properties.
Maybe there is an alternative solution to this problem I'm not seeing, i'm open to all suggestions.
Audit entity class
public class AuditLog
{
public int Id { get; set; }
public string Description { get; set; }
public string OldValue { get; set; }
public string NewValue { get; set; }
public string PropertyName { get; set; }
public DateTime AuditDateTime { get; set; }
public Guid? AuditIssuerUserId { get; set; }
public string AuditAction { get; set; }
public string TableName { get; set; }
public int TablePK { get; set; }
}
Startup configuration
Audit.Core.Configuration.Setup()
.UseCustomProvider(new CustomEntityFrameworkDataProvider(x => x
.AuditEntityAction<AuditLog>((ev, ent, auditEntity) =>
{
auditEntity.AuditDateTime = DateTime.Now;
auditEntity.AuditAction = ent.Action;
foreach(var change in ent.Changes)
{
auditEntity.OldValue = change.OriginalValue.ToString();
auditEntity.NewValue = change.NewValue.ToString();
auditEntity.PropertyName = change.ColumnName;
}
}
Custom data provider class
public class CustomEntityFrameworkDataProvider : EntityFrameworkDataProvider
{
public override object InsertEvent(AuditEvent auditEvent)
{
var auditEventEf = auditEvent as AuditEventEntityFramework;
if (auditEventEf == null)
return null;
object result = null;
foreach (var entry in auditEventEf.EntityFrameworkEvent.Entries)
{
if (entry.Changes == null || entry.Changes.Count == 0)
continue;
foreach (var change in entry.Changes)
{
var contextHelper = new DbContextHelper();
var newEfEvent = contextHelper.CreateAuditEvent((IAuditDbContext)auditEventEf.EntityFrameworkEvent.GetDbContext());
if (newEfEvent == null)
continue;
newEfEvent.Entries = new List<EventEntry>() { entry };
entry.Changes = new List<EventEntryChange> { change };
auditEventEf.EntityFrameworkEvent = newEfEvent;
result = base.InsertEvent(auditEvent);
}
}
return result;
}
}
Check my answer here https://github.com/thepirat000/Audit.NET/issues/323#issuecomment-673007204
You don't need to call CreateAuditEvent() you should be able to iterate over the Changes list on the original event and call base.InsertEvent() for each change, like this:
public override object InsertEvent(AuditEvent auditEvent)
{
var auditEventEf = auditEvent as AuditEventEntityFramework;
if (auditEventEf == null)
return null;
object result = null;
foreach (var entry in auditEventEf.EntityFrameworkEvent.Entries)
{
if (entry.Changes == null || entry.Changes.Count == 0)
continue;
// Call base.InsertEvent for each change
var originalChanges = entry.Changes;
foreach (var change in originalChanges)
{
entry.Changes = new List<EventEntryChange>() { change };
result = base.InsertEvent(auditEvent);
}
entry.Changes = originalChanges;
}
return result;
}
Notes:
This could impact performance, since it will trigger an insert to the database for each column change.
If you plan to use async calls to DbContext.SaveChangesAsync, you should also implement the InsertEventAsync method on your CustomDataProvider
The Changes property is only available for Updates, so if you also want to audit Inserts and Deletes, you'll need to add the logic to get the column values from the ColumnValues property on the event
I have this model:
And I want to add a new Autor like below:
class Program
{
static void Main(string[] args)
{
try
{
AutorServiceClient service = new AutorServiceClient();
LivroContract[] livros = {
new LivroContract { id_tipo = 1, nome_livro = "Asp.Net MVC 5" },
new LivroContract { id_tipo = 1, nome_livro = "Asp.Net Entity Framework" }
};
AutorContract autorContract = new AutorContract()
{
nome_autor = "Novo Autor",
Livros = livros
};
if (service.Add(autorContract))
Console.WriteLine("Adicionado com Sucesso");
}
catch (Exception)
{
Console.WriteLine("Erro !!!");
}
}
}
My Autor class has a nested Livro collection and I want to insert a new Autor with its respective Livro entities.
Below is part of my Data Access code to make the insert:
public class AutorDA
{
private readonly BibliotecaEntities _context;
private readonly DbSet<Autor> _dbSet;
public AutorDA()
{
_context = new BibliotecaEntities();
_dbSet = _context.Set<Autor>();
Mapping();
}
public void Mapping()
{
Mapper.Initialize(cfg =>
{
cfg.CreateMap<Autor, AutorDTO>();
cfg.CreateMap<AutorDTO, Autor>();
cfg.CreateMap<ICollection<Autor>, IEnumerable<AutorDTO>>();
cfg.CreateMap<IEnumerable<AutorDTO>, ICollection<Autor>>();
cfg.CreateMap<Biblioteca, BibliotecaDTO>();
cfg.CreateMap<BibliotecaDTO, Biblioteca>();
cfg.CreateMap<ICollection<Biblioteca>, IEnumerable<BibliotecaDTO>>();
cfg.CreateMap<IEnumerable<BibliotecaDTO>, ICollection<Biblioteca>>();
cfg.CreateMap<Livro, LivroDTO>();
cfg.CreateMap<LivroDTO, Livro>();
cfg.CreateMap<ICollection<Livro>, IEnumerable<LivroDTO>>();
cfg.CreateMap<IEnumerable<LivroDTO>, ICollection<Livro>>();
cfg.CreateMap<Tipo_Livro, TipoLivroDTO>();
cfg.CreateMap<TipoLivroDTO, Tipo_Livro>();
cfg.CreateMap<ICollection<Tipo_Livro>, IEnumerable<TipoLivroDTO>>();
cfg.CreateMap<IEnumerable<TipoLivroDTO>, ICollection<Tipo_Livro>>();
});
}
public bool Add(AutorDTO dto)
{
try
{
Mapping();
Autor autor = Mapper.Map<Autor>(dto);
_dbSet.Add(autor);
_context.SaveChanges();
return true;
}
catch (Exception ex)
{
throw ex;
}
}
....
Here is my DTOs:
public class AutorDTO
{
public int id { get; set; }
public string nome_autor { get; set; }
public IEnumerable<LivroDTO> Livros { get; set; }
}
public class LivroDTO
{
public int id { get; set; }
public int id_tipo { get; set; }
public string nome_livro { get; set; }
public ICollection<AutorDTO> Autores { get; set; }
public ICollection<BibliotecaDTO> Bibliotecas { get; set; }
public TipoLivroDTO TipoLivro { get; set; }
}
I know that there is something wrong here, but I dont know what... I am trying to insert Autor and a couple of Livros entities, but I dont know how to do that, using AutoMapper and EF.
But with this code, I am only inserting Autor.
So, I have two situations I dont know how to do:
Insert a new Autor and new Livro entities
Insert a new Autor and associate it with already inserted Livro entities
How I configure AutoMapper to those two situations above ?
Finally, my last questions are:
What is the better approach for situations where we have a main entity, which has one or more child entities (1:n / n:n) ?
Is it a good idea to insert/update simultanneosly all those entities, or it is a bad idea ? If it is a bad idea, so what is best way to do insert a main class and its relations ?
As we can see, my Livro entity has other child relations, but I want to use only Autor and Livro. I need to map all model/entities just to use those two ones ?
Thanks.
I have a A Table, B Table and AB (Mapping Table)
A
public class A
{
public int AID{ get; set; }
[JsonIgnore]
public virtual ICollection<B> Bs { get; set; }
}
B
public class B
{
public int BID { get; set; }
[JsonIgnore]
public virtual ICollection<A> As { get; set; }
}
ApplicationDbContext
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Entity<B>()
.HasMany(s => s.As)
.WithMany(c => c.Bs)
.Map(cs =>
{
cs.MapLeftKey("AID");
cs.MapRightKey("BID");
cs.ToTable("AB");
});
}
Now things are perfectly fine, but how do I insert in this AB Mapping table?
If I try to create AB as like below, it generates two tables, AB and AB1 with same column name and all.
public class AB
{
public int ABID { get; set; }
public string AID { get; set; }
public int BID { get; set; }
}
So is there any way to do CRUD in FluentAPI Mapping Table?
If not, then can I force FluentAPI to map from Existing table? In this case I'll manually manage Employee and will change the mapping code to use existing table.
I'm unable to find any of the solution.
Edit: Since the question was changed, I'm writing up a more thorough answer. The answer to your question remains the same, however:
Now things are perfectly fine, but how do I insert in this AB Mapping
table?
You don't!
This is exactly the kind of thing that EF is good at. Instead of managing a link table yourself, now you just end up with the actual object you want. So, if you want to add a link between an A and B, all you do is add a B to the Bs collection on that A. You don't ever insert directly into the AB table, because who cares about that? That table is there so we can have relationships between different As and Bs, that's it. So, Entity Framework will create the table for it's own use, but not present it to you, because that's not how EF works: you work with your objects and let EF handle the database.
That's why when you try to define the table yourself, it creates two: it's already making a table called AB, but you're asking for another one. It can't have exactly the same name so it appends a '1' to the end of it. Since you've already used FluentAPI to define the apping, let EF worry about how to implement the mapping: all you need to care about is that you've now got a way to have an A with a set of Bs, or vice versa.
Since this still sounds confusing with names 'A' and 'B', below is the Program class for a console app that will illustrate this; all you need to do is start a fresh console app, replace the Program class with this one, install the entity framework package, and run enable-migrations -enableautomaticmigrations -force. I recommend you use this to add some objects and relate them, and then go have a look at your database: you will see the 'AB' table, with records that were added. This might help explain it better.
class Program
{
static bool quit = false;
static void Main(string[] args)
{
string s = "Please select an option:" +
"\n1: Insert an A" +
"\n2: Insert a B" +
"\n3: Add a B to an A" +
"\n4: Add an A to a B" +
"\n5: Print all As" +
"\n6: Print all Bs" +
"\n7: Print AB Table" +
"\nx: Quit.";
while (!quit)
{
Console.WriteLine();
Console.WriteLine(s);
var k = Console.ReadKey();
DoStuff(k);
}
}
private static void DoStuff(ConsoleKeyInfo i)
{
switch (i.Key)
{
case ConsoleKey.D1:
//add an A
AddA(GetName());
break;
case ConsoleKey.D2:
//add a B
AddB(GetName());
break;
case ConsoleKey.D3:
// link a B to an A
LinkB(GetBtoLink(),GetAtoLink());
break;
case ConsoleKey.D4:
//link an A to an B
LinkA(GetAtoLink(), GetBtoLink());
break;
case ConsoleKey.D5:
// print As
WriteA();
break;
case ConsoleKey.D6:
//print Bs
WriteB();
break;
case ConsoleKey.D7:
// print AB
WriteAB();
break;
case ConsoleKey.X:
quit = true;
break;
}
}
private static int GetAtoLink()
{
string x;
int z;
do
{
Console.Clear();
Console.WriteLine("Please enter the ID of the A you want to use and then press enter.");
WriteA();
x = Console.ReadLine();
} while (!int.TryParse(x, out z));
return z;
}
private static int GetBtoLink()
{
string x;
int z;
do
{
Console.Clear();
Console.WriteLine("Please enter the ID of the B you want to use and then press enter.");
WriteB();
x = Console.ReadLine();
} while (!int.TryParse(x, out z));
return z;
}
private static void WriteB()
{
Console.WriteLine("{0,10}{1,15}", "ID", "Name");
using (var db = new Context())
{
foreach (var a in db.Bs)
{
Console.WriteLine("{0,10}{1,15}", a.BID, a.Name);
}
}
}
private static void WriteA()
{
Console.WriteLine("{0,10}{1,15}", "ID", "Name");
using (var db = new Context())
{
foreach (var a in db.As)
{
Console.WriteLine("{0,10}{1,15}", a.AID, a.Name);
}
}
}
private static void WriteAB()
{
Console.WriteLine("{0,10}{1,10}", "AID", "BID");
using (var db = new Context())
{
// this is the only way we need to do this, because it's many to many,
// if an A is linked to a B, then that B is by definition linked to that A as well.
foreach (var a in db.As)
{
foreach (var b in a.Bs)
{
Console.WriteLine("{0,10}{1,10}", a.AID, b.BID);
}
}
}
}
private static void LinkB(int bToUse, int aToUse)
{
using (var db = new Context())
{
var a = db.As.First(x => x.AID == aToUse);
var b = db.Bs.First(y => y.BID == bToUse);
a.Bs.Add(b);
db.SaveChanges();
}
}
private static void LinkA(int aToUse, int bToUse)
{
using (var db = new Context())
{
var a = db.As.First(x => x.AID == aToUse);
var b = db.Bs.First(y => y.BID == bToUse);
b.As.Add(a);
db.SaveChanges();
}
}
private static string GetName()
{
Console.WriteLine("Please enter a name");
return Console.ReadLine();
}
private static void AddA(string input)
{
using (var db = new Context())
{
db.As.Add(new A {Name = input});
db.SaveChanges();
}
}
private static void AddB(string input)
{
using (var db = new Context())
{
db.Bs.Add(new B { Name = input });
db.SaveChanges();
}
}
}
public class A
{
public int AID { get; set; }
public string Name { get; set; }
public virtual ICollection<B> Bs { get; set; }
}
public class B
{
public int BID { get; set; }
public string Name { get; set; }
public virtual ICollection<A> As { get; set; }
}
public class Context : DbContext
{
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Entity<B>()
.HasMany(s => s.As)
.WithMany(c => c.Bs)
.Map(cs =>
{
cs.MapLeftKey("AID");
cs.MapRightKey("BID");
cs.ToTable("AB");
});
}
public DbSet<A> As { get; set; }
public DbSet<B> Bs { get; set; }
}
Old Answer: You've defined an ICollection<ApplicationUser> called Employees in Company, and mapped to it with FluentAPI. This creates a table called 'Employees' as expected. You don't have to create another class called Employees; as far as Entity Framework is concerned, you've already told it to create a table called Employees. This is why
I think the step you're missing is defining your DbSet<>.
Using your code, and running Add-Migration, this is the definition I get for the Employees table:
CreateTable(
"dbo.Employees",
c => new
{
UserID = c.Int(nullable: false),
CompanyID = c.Int(nullable: false),
})
.PrimaryKey(t => new { t.UserID, t.CompanyID })
.ForeignKey("dbo.ApplicationUsers", t => t.UserID, cascadeDelete: true)
.ForeignKey("dbo.Companies", t => t.CompanyID, cascadeDelete: true)
.Index(t => t.UserID)
.Index(t => t.CompanyID);
Which seems to correlate with what you wanted.
To finish it off, add (if you haven't already) this to your ApplicationDbContext file:
public DbSet<ApplicationUser> Employees;
public DbSet<Company> Companies;
Then to add an employee, you create a new ApplicationUser and add it like
ApplicationUser user = new ApplicationUser();
// do whatever here to give it the right data
ApplicationDbContext ctx = new ApplicationDbContext();
ctx.Employees.Add(user);
The Employees table itself you shouldn't ever have to interact with.
EF will manage that you don't need to insert into the mapping table directly, have a look at this sample that I have in my project:
public class Organization : Entity<int>
{
public string Name { get; set; }
public string Address { get; set; }
public string MainContact { get; set; }
public string Phone { get; set; }
public string Website { get; set; }
//navigation property
public virtual ICollection<DevelopmentalGoal> DevelopmentalGoals { get; set; }
public virtual ICollection<ServiceActivity> ServiceActivities { get; set; }
}
public class DevelopmentalGoal : Entity<int>
{
public string Name { get; set; }
public string Icon { get; set; }
//navigation property
public virtual ICollection<Organization> Organizations { get; set; }
}
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Organization>().ToTable("Organization", "ServiceLearning")
.HasKey(t => t.ID);
modelBuilder.Entity<DevelopmentalGoal>().ToTable("DevelopmentalGoal", "ServiceLearning")
.HasKey(t => t.ID);
modelBuilder.Entity<Organization>()
.HasMany(t => t.DevelopmentalGoals)
.WithMany(t=> t.Organizations)
.Map(m =>
{
m.ToTable("OrganizationDevelopmentalGoal", "ServiceLearning");
m.MapLeftKey("OrganizationID");
m.MapRightKey("DevelopmentalGoalID");
});
}
public int SaveOrganization(OrganizationViewModel viewModel, IUserContext currentUser)
{
Organization organization;
{
if (viewModel.ID == 0)
{
organization = ObjectMapper.MapTo<Organization>(viewModel);
_context.Set<Organization>().Add(organization);
}
else
{
organization = _context.Set<Organization>()
.SingleOrDefault(t =>
t.ID == viewModel.ID
);
organization.Name = viewModel.Name;
organization.Address = viewModel.Address;
organization.MainContact = viewModel.MainContact;
organization.Phone = viewModel.Phone;
organization.Website = viewModel.Website;
UpdateOrganizationDevelopmentalGoals(organization, viewModel);
}
try
{
CommitChanges();
}
catch (DbUpdateException ex)
{
if (ex.IsDuplicateException())
throw new KeystoneDuplicateException("A Organization with the same name already exists.");
throw ex;
}
}
return organization.ID;
}
private void UpdateOrganizationDevelopmentalGoals(Organization organization, OrganizationViewModel viewModel)
{
var originalIdList = organization.DevelopmentalGoals.Select(d => d.ID).Distinct().ToList();
var modifiedIdList = viewModel.DevelopmentalGoal.Where(d => d.Selected == true).Select(d => d.ID).Distinct().ToList();
//Remove deleted Developmetal Goals.
foreach (var id in originalIdList.Except(modifiedIdList))
organization.DevelopmentalGoals.Remove(organization.DevelopmentalGoals.Single(d => d.ID == id));
//Add new Developmetal Goals.
foreach (var id in modifiedIdList.Except(originalIdList))
{
//Add director relationship without having to load entity.
var d = new DevelopmentalGoal { ID = id };
_context.Set<DevelopmentalGoal>().Attach(d);
organization.DevelopmentalGoals.Add(d);
}
}
As you can see in the UpdateOrganizationDevelopmentalGoals method I do not insert or delete data from the mapping table directly, I insert and delete from the organization.DevelopmentalGoals and as I've already defined the mapping table in fluent API on "OnModelCreating" then EF knows how to manage the relations.
I have an EF6 setup against a sql server db with about 60 tables in it.
I have entities for each table. What i'm trying to do is run the same method against a set of these entities that will be known at runtime.
The method is a qa/qc routine that does some data check on particular fields that are assured to be in each table.
I guess what i want to do is make the entity a parameter to the method so i can call it consecutive times.
I would also want to make a set of entities to pass as the parameter.
something like this:
List<string> entList = new List<string>(){"Table1","Table2","Table3"};
foreach (entName in entList)
{
//create an entity with the string name
//call myQAQCMethod with the entity
}
MyQAQCMethod (entity SomeEntity)
{
//run against this entity
doQAQC(SomeEntity);
}
Can this be done? Is it a job for reflection?
EDIT
using (var context = new Context())
{
var results = context.EntityAs.Where(a => a.Prop1 == e.Prop1)
.Where(a => a.Prop2 == e.Prop2)
.Select(a => new
{
APropertyICareAbout = a.Prop1,
AnotherPropertyICareAbout = a.Prop2
}).ToArray();
}
is precisely want i want to do. The thing is I want to avoid typing this loop 60 times. I think i'm looking for a way to "feed" a set of entities to this single method.
Also, thank you very much for helping me. I'm learning a lot.
You need to abstract an interface (entity framework won't even notice):
interface IQaQcable
{
int CommonInt { get; set; }
string CommonString { get; set; }
}
public class EntityA : IQaQcable
{
public int Id { get; set; }
public int CommonInt { get; set; }
public string CommonString { get; set; }
// other properties and relations
}
public class EntityB : IQaQcable
{
public int Id { get; set; }
public int CommonInt { get; set; }
public string CommonString { get; set; }
// other properties and relations
}
// in some unknown utility class
void MyQaQcMethod<T>(T entity) where T : IQaQcable
{
doSomethingWithIQaQcableProperties(entity.CommonInt, entity.CommonString);
}
// in some unknown test class
void Test()
{
var entities = new List<IQaQcable> { new EntityA(), new EntityB() };
foreach (var e in entities)
MyQaQcMethod(e);
}
Now, you could extract a base class from which each derives that actually implements the CommonInt and CommonString properties for each entity needing them, but that can get kind of tricky with Table-Per-Type/Table-Per-Hierarchy, so I'd start with this, and then consider introducing either an abstract or concrete base class as an improvement.
EDIT
Maybe your looking for something simpler than I first thought, based on your last comment.
Let's give ourselves what the DbContext for this might look like:
class Context : DbContext
{
public virtual DbSet<EntityA> EntityAs { get; set; }
public virtual DbSet<EntityB> EntityBs { get; set; }
}
So, it could just be that you wish to do this:
using (var context = new Context())
{
var results = context.EntityAs.Where(a => a.Prop1 == e.Prop1)
.Where(a => a.Prop2 == e.Prop2)
.Select(a => new
{
APropertyICareAbout = a.Prop1,
AnotherPropertyICareAbout = a.Prop2
}).ToArray();
}
Keeping in mind, if there is some set of properties in common across entity classes, you could still do something like the following:
IEnumerable<T> MyQaQcMethod(IQueryable<T> entities, T referenceEntity) where T : IQaQcAble
{
return entities.Where(e => SomePredicate(e, referenceEntity));
}
void Test()
{
using (var context = new Context())
{
// EntityA implements IQaQcAble
var resultsForA = MyQaQcMethod(context.EntityAs, defaultEntity).ToArray();
// so does EntityB, so can call with either
var resultsForB = MyQaQcMethod(context.EntityBs, defaultEntity).ToArray();
}
}
Keep in mind, to avoid modifying the generated entity classes, you could implement the interface members — and the interface — in a separate source file using partial classes. E.g.
// IQaQcAble.cs
internal interface IQaQcAble
{
int CommonInt { get; set; }
string CommonString { get; set; }
}
// a class whose existing property names match the interface
public partial class EntityA : IQaQcAble
{
int IQaQcAble.CommonInt
{
get { return CommonInt; }
set { CommonInt = value; }
}
string IQaQcAble.CommonString
{
get { return CommonString; }
set { CommonString = value; }
}
}
// a class whose property names differ
public partial class EntityB : IQaQcAble
{
int IQaQcAble.CommonInt
{
get { return SomeOtherInt; }
set { SomeOtherInt = value; }
}
string IQaQcAble.CommonString
{
get { return SomeOtherInt.ToString(); }
set { SomeOtherInt = Convert.ToInt32(value); }
}
}