net web app in witch database first and in my models they made the join tables as models. The thing that i want to do is that when i save ore edit a normal model i want to be able to update the relationships ass well. The problem is that i have a lot of repetitive code.For instance:
for (int i = 0; i < formationVM.Traits_.Length; i++)
{
_context.FormationTraits.Add(new FormationTrait(formationVM.Formation_, await _context.Traits.FirstOrDefaultAsync(q => q.Id == formationVM.Traits_[i])));
}
for (int i = 0; i < formationVM.Factions_.Length; i++)
{
_context.FactionFormations.Add(new FactionFormation(await _context.Factions.FirstOrDefaultAsync(q => q.Id == formationVM.Factions_[i]), formationVM.Formation_));
}
for (int i = 0; i < formationVM.Items_.Length; i++)
{
_context.ItemFormations.Add(new ItemFormation(await _context.Items.FirstOrDefaultAsync(q => q.Id == formationVM.Items_[i]), formationVM.Formation_));
}
So i want to make a single function that dose all the 3 repetitive task.
I thought of using abstraction in order to do this.
public interface IJointModel
{
public int IdLeft { get; set; }
public int IdRight { get; set; }
public IModel_ GetIdNavigationLeftModel();
public void SetIdNavigationLeftModel(IModel_ modelLeft);
public IModel_ GetIdNavigationRightModel();
public void SetIdNavigationRightModel(IModel_ modelRight);
public void saveYourself(TotalWarWanaBeContext context);
}
public interface IModel_
{
public int Id { get; set; }
}
public partial class Formation : IModel_
public partial class Trait :IModel_
public partial class FormationTrait : IJointModel{
public FormationTrait(Formation formation, Trait trait)
{
this.IdFormationNavigation = formation;
this.IdTraitNavigation = trait;
this.IdRight = trait.Id;
this.IdLeft = formation.Id;
}
[ForeignKey("IdFormationNavigation")]
[Column("IdFormation")]
public int IdLeft { get; set; }
[ForeignKey("IdTraitNavigation")]
[Column("IdTrait")]
public int IdRight { get; set; }
public virtual Formation IdFormationNavigation { get; set; }
public virtual Trait IdTraitNavigation { get; set; }
#region "Get_set_IJoinModel"
public IModel_ GetIdNavigationLeftModel()
{
return this.IdFormationNavigation;
}
public IModel_ GetIdNavigationRightModel()
{
return this.IdTraitNavigation;
}
public void SetIdNavigationLeftModel(IModel_ modelLeft)
{
this.IdFormationNavigation = (Formation)modelLeft;
}
public void SetIdNavigationRightModel(IModel_ modelRight)
{
this.IdTraitNavigation = (Trait)modelRight;
}
#endregion
public void saveYourself(TotalWarWanaBeContext context)
{
context.FormationTraits.Add(this);
}
}
The end goal is so that i can make the function
private void saveRelation(string jointableType/* ore something like this*/, IModel anyModel, int[] idLeftModels){
for(int i = 0; i < idLeftModels.Length; i++){
IJointModel jointModel = new IJointModel.TypeOf(jointTableType);
jointModel.setIdNavigationLeftModel = anyModel;
jointModel.setItNavigtionRightModel = _context.DbSetofTypeINeed.where(t => t.id = idLeftModels[i];
jointModel.SaveYourself();
}
How can I make the function saveRelation save in the database any Model that inherits from IJoinModel. Sorry if the title is miss representative but i didn't know how to phrase it
Related
I want to implement something similar to lazy loading, but don't understand how to implement that. I want to force entity framework core include navigation property for all queries for type which implements my interface
public interface IMustHaveOrganisation
{
Guid OrganisationId { get; set; }
Organisation Organisation { get; set; }
}
public class MyEntity : IMustHaveOrganisation {
public Guid OrganisationId { get; set; }
public virtual Organisation Organisation { get; set; }
}
Without lazy loading I need to add .Include(x=>x.Organisation) to each query literally , and I can't use implementation of lazy loading provided by Microsoft. I need kind of custom implementation of that with loading just one property.
Or even force DbContext somehow to Include that property, it also fine for me.
How can I achieve that?
You can make this work by rewriting the expression tree, before it gets translated by EF Core.
To make this work in a way, where you don't have to specify anything additional in the query, you can hook into the very beginning of the query pipeline and inject the Include() call as needed.
This can be done, by specifying a custom IQueryTranslationPreprocessorFactory implementation.
The following fully working console project demonstrates this approach:
using System.Diagnostics;
using System.Linq;
using System.Linq.Expressions;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Query;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
namespace IssueConsoleTemplate
{
public class Organisation
{
public int OrganisationId { get; set; }
public string Name { get; set; }
}
public interface IMustHaveOrganisation
{
int OrganisationId { get; set; }
Organisation Organisation { get; set; }
}
public class MyEntity : IMustHaveOrganisation
{
public int MyEntityId { get; set; }
public string Name { get; set; }
public int OrganisationId { get; set; }
public virtual Organisation Organisation { get; set; }
}
public class CustomQueryTranslationPreprocessorFactory : IQueryTranslationPreprocessorFactory
{
private readonly QueryTranslationPreprocessorDependencies _dependencies;
private readonly RelationalQueryTranslationPreprocessorDependencies _relationalDependencies;
public CustomQueryTranslationPreprocessorFactory(
QueryTranslationPreprocessorDependencies dependencies,
RelationalQueryTranslationPreprocessorDependencies relationalDependencies)
{
_dependencies = dependencies;
_relationalDependencies = relationalDependencies;
}
public virtual QueryTranslationPreprocessor Create(QueryCompilationContext queryCompilationContext)
=> new CustomQueryTranslationPreprocessor(_dependencies, _relationalDependencies, queryCompilationContext);
}
public class CustomQueryTranslationPreprocessor : RelationalQueryTranslationPreprocessor
{
public CustomQueryTranslationPreprocessor(
QueryTranslationPreprocessorDependencies dependencies,
RelationalQueryTranslationPreprocessorDependencies relationalDependencies,
QueryCompilationContext queryCompilationContext)
: base(dependencies, relationalDependencies, queryCompilationContext)
{
}
public override Expression Process(Expression query)
{
query = new DependenciesIncludingExpressionVisitor().Visit(query);
return base.Process(query);
}
}
public class DependenciesIncludingExpressionVisitor : ExpressionVisitor
{
protected override Expression VisitConstant(ConstantExpression node)
{
// Call Include("Organisation"), if SomeEntity in a
// DbSet<SomeEntity> implements IMustHaveOrganisation.
if (node.Type.IsGenericType &&
node.Type.GetGenericTypeDefinition() == typeof(Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryable<>) &&
node.Type.GenericTypeArguments.Length == 1 &&
typeof(IMustHaveOrganisation).IsAssignableFrom(node.Type.GenericTypeArguments[0]))
{
return Expression.Call(
typeof(EntityFrameworkQueryableExtensions),
nameof(EntityFrameworkQueryableExtensions.Include),
new[] {node.Type.GenericTypeArguments[0]},
base.VisitConstant(node),
Expression.Constant(nameof(IMustHaveOrganisation.Organisation)));
}
return base.VisitConstant(node);
}
}
public class Context : DbContext
{
public DbSet<MyEntity> MyEntities { get; set; }
public DbSet<Organisation> Organisations { get; set; }
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
// Register the custom IQueryTranslationPreprocessorFactory implementation.
// Since this is a console program, we need to create our own
// ServiceCollection for this.
// In an ASP.NET Core application, the AddSingleton call can just be added to
// the general service configuration method.
var serviceProvider = new ServiceCollection()
.AddEntityFrameworkSqlServer()
.AddSingleton<IQueryTranslationPreprocessorFactory, CustomQueryTranslationPreprocessorFactory>()
.AddScoped(
s => LoggerFactory.Create(
b => b
.AddConsole()
.AddFilter(level => level >= LogLevel.Information)))
.BuildServiceProvider();
optionsBuilder
.UseInternalServiceProvider(serviceProvider) // <-- use our ServiceProvider
.UseSqlServer(#"Data Source=.\MSSQL14;Integrated Security=SSPI;Initial Catalog=62849896")
.EnableSensitiveDataLogging()
.EnableDetailedErrors();
}
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<MyEntity>(
entity =>
{
entity.HasData(
new MyEntity {MyEntityId = 1, Name = "First Entity", OrganisationId = 1 },
new MyEntity {MyEntityId = 2, Name = "Second Entity", OrganisationId = 1 },
new MyEntity {MyEntityId = 3, Name = "Third Entity", OrganisationId = 2 });
});
modelBuilder.Entity<Organisation>(
entity =>
{
entity.HasData(
new Organisation {OrganisationId = 1, Name = "First Organisation"},
new Organisation {OrganisationId = 2, Name = "Second Organisation"});
});
}
}
internal static class Program
{
private static void Main()
{
using var context = new Context();
context.Database.EnsureDeleted();
context.Database.EnsureCreated();
var myEntitiesWithOrganisations = context.MyEntities
.OrderBy(i => i.MyEntityId)
.ToList();
Debug.Assert(myEntitiesWithOrganisations.Count == 3);
Debug.Assert(myEntitiesWithOrganisations[0].Name == "First Entity");
Debug.Assert(myEntitiesWithOrganisations[0].Organisation.Name == "First Organisation");
}
}
}
Even though no explicit Include() is being made in the query in Main(), the following SQL is being generated, that does join and retrieve the Organisation entities:
SELECT [m].[MyEntityId], [m].[Name], [m].[OrganisationId], [o].[OrganisationId], [o].[Name]
FROM [MyEntities] AS [m]
INNER JOIN [Organisations] AS [o] ON [m].[OrganisationId] = [o].[OrganisationId]
ORDER BY [m].[MyEntityId]
I have multiple databases, 1 common and n company db. I use code first with one migration for common and one for the companies db.
I have a base context this is inherit to 2 contexts (common, company). I try to use only the base context and remove the specified contexts, so far no problem.
My problem is following, if i try to use linq on context.Set<> then I get an InvalidOperationException "The entity type NOCompany is not part of the model for the current context".
using (NOContext db = new NOContext(connection)) {
var dbset = db.Set<NOCompany>()
.Where(company => (company.Deleted == null) || (company.Deleted == false));
foreach (var item in dbset) {
System.Diagnostics.Debug.WriteLine(item.Matchcode);
}
}
if I use this
using (NOContext db = new NOCommonContext(connection)) {
var dbset = db.Set<NOCompany>()
.Where(company => (company.Deleted == null) || (company.Deleted == false));
foreach (var item in dbset) {
System.Diagnostics.Debug.WriteLine(item.Matchcode);
}
}
then it works fine. Where is the problem?
Following excerpt from the classes
public class NOContext : DbContext, INOContext
{
public NOContext() { }
public NOContext(string connection) : base(connection) { }
#region - override DbContext -
public override int SaveChanges()
{
foreach (var entry in ChangeTracker.Entries<EntityBase>()) {
DateTime currentDateTime = DateTime.Now;
var entity = entry.Entity;
if (entry.State == EntityState.Added) {
entity.CreateDate = currentDateTime;
entity.CreateId = NOEngine.SessionInfo.CurrentUserId;
} else if (entry.State == EntityState.Deleted) {
entry.State = EntityState.Modified;
entity.Deleted = true;
entity.DeletedDate = currentDateTime;
entity.DeletedId = NOEngine.SessionInfo.CurrentUserId;
}
entity.ModifiedDate = currentDateTime;
entity.ModifiedId = NOEngine.SessionInfo.CurrentUserId;
}
return base.SaveChanges();
}
#endregion
//database methods
}
Then I have 2 specified context
public class NOCommonContext : NOContext
{
public const string CommonCatalog = "NOCommonDb";
public NOCommonContext() { }
public NOCommonContext(string connection) : base(connection) { }
#region - DbSets -
public virtual DbSet<NOUser> Users { get; set; }
public virtual DbSet<NOCompany> Companies { get; set; }
public virtual DbSet<NOConfig> AppConfiguration { get; set; }
#endregion //DbSets
}
and
public partial class NOAppContext : NOContext
{
public NOAppContext() { }
public NOAppContext(string connection) : base(connection) { }
#region - DbSets -
public virtual DbSet<BPCard> BPCards { get; set; }
public virtual DbSet<BPContact> BPContacts { get; set; }
public virtual DbSet<HRCard> HRCards { get; set; }
#endregion //DbSets
}
I am trying to get the value of a "NotMapped" property for a Entity/class when intercepting a DbUpdateCommandTree.
I have looked through the various metadata, but I cannot find the "link" to the Entity from the CommandTree, so unfortunately I am stuck.
Is it even possible ?
public class SomeEntity
{
public int ID { get; set; }
[NotMapped]
public int SomeUnmappedProperty { get; set; }
}
public class CommandTreeInterceptor : IDbCommandTreeInterceptor
{
public void TreeCreated(DbCommandTreeInterceptionContext ctx)
{
if (ctx.OriginalResult.DataSpace == DataSpace.SSpace)
{
var updateCommand = ctx.OriginalResult as DbUpdateCommandTree;
if (updateCommand != null)
{
// I would like to get a value of a specific property here.
// Pseudo code
var val = updateCommand.Entity.GetPropertyValue("SomeUnmappedProperty") as int;
}
}
}
}
In Entity framework I have objectsets like
public partial class Building
{
public int BuildingID { get; set; }
public string BuildingName { get; set; }
}
public partial class Town
{
public int TownID { get; set; }
public string TownName { get; set; }
}
I want to create a generic query like
T.OrderBy(o=>o.Id).Skip(maxDispItem * (page - 1)).Take(maxDispItem).ToList();
T is generic class can be Building or Town but problem is BuildingId and TownId has different name.I don't want to change their name as Id and create interface IIdentity.
Maybe you could try something like this:
var query = (typeof(T) == typeof(Building) ?
context.Buildings.Select(b => new { Id = b.BuildingId, Name = b.BuildingName }) :
context.Towns.Select(t => new { Id = t.TownId, Name = b.TownName }))
.OrderBy(o => o.Id)...
Not tested but that's worth a test...
You can create generic method which find a field decorated with KeyAttribute, and then performs sorting by found key field. I have tested your model, works perfectly. Look at code snippet.
DbContext:
using System.Collections.Generic;
using System.Data.Entity;
namespace ConsoleApplication28.Entities
{
public class AppDbContext : DbContext
{
public AppDbContext()
{
Database.Connection.ConnectionString = #"Data Source=NOTEBOOK-PC;Initial Catalog=StackOverflowTest;Integrated Security=True";
Database.SetInitializer(new AppDbInitializer());
}
public DbSet<Town> Towns { get; set; }
public DbSet<Building> Buildings { get; set; }
}
public class AppDbInitializer : DropCreateDatabaseIfModelChanges<AppDbContext>
{
protected override void Seed(AppDbContext context)
{
context.Buildings.AddRange(new List<Building>
{
new Building {BuildingName = "Building1"},
new Building {BuildingName = "Building2"},
});
context.Towns.AddRange(new List<Town>
{
new Town {TownName = "Town1"},
new Town {TownName = "Town2"},
});
context.SaveChanges();
base.Seed(context);
}
}
}
Building
using System.ComponentModel.DataAnnotations;
namespace ConsoleApplication28.Entities
{
public class Building
{
[Key]
public int BuildingID { get; set; }
public string BuildingName { get; set; }
}
}
Town
using System.ComponentModel.DataAnnotations;
namespace ConsoleApplication28.Entities
{
public class Town
{
[Key]
public int TownID { get; set; }
public string TownName { get; set; }
}
}
Program
using System;
using System.Linq;
using System.Linq.Expressions;
using System.Reflection;
using ConsoleApplication28.Entities;
using System.ComponentModel.DataAnnotations;
namespace ConsoleApplication28
{
class Program
{
static void Main(string[] args)
{
const int maxDispItem = 10;
const int page = 1;
var db = new AppDbContext();
var towns = db.Towns.OrderByKey().Skip(maxDispItem * (page - 1)).Take(maxDispItem).ToList();
var buildings = db.Buildings.OrderByKey().Skip(maxDispItem * (page - 1)).Take(maxDispItem).ToList();
}
}
public static class Extensions
{
/// <summary>
/// Sorts the elements of a sequence in ascending order according to a key specified using KeyAttribute
/// </summary>
public static IOrderedQueryable<T> OrderByKey<T>(this IQueryable<T> source, bool isAsc = true)
{
var type = typeof(T);
var keyProperty = type.GetProperties().Single(x => x.GetCustomAttributes(typeof(KeyAttribute)).Any());
return source.OrderBy(keyProperty.Name, isAsc);
}
#region COPIED FROM THERE http://stackoverflow.com/questions/41244/dynamic-linq-orderby-on-ienumerablet
public static IOrderedQueryable<T> OrderBy<T>(this IQueryable<T> source, string property, bool isAsc)
{
return isAsc ? source.OrderBy(property) : source.OrderByDescending(property);
}
public static IOrderedQueryable<T> OrderBy<T>(this IQueryable<T> source, string property)
{
return ApplyOrder<T>(source, property, "OrderBy");
}
public static IOrderedQueryable<T> OrderByDescending<T>(this IQueryable<T> source, string property)
{
return ApplyOrder<T>(source, property, "OrderByDescending");
}
public static IOrderedQueryable<T> ThenBy<T>(this IOrderedQueryable<T> source, string property)
{
return ApplyOrder<T>(source, property, "ThenBy");
}
public static IOrderedQueryable<T> ThenByDescending<T>(this IOrderedQueryable<T> source, string property)
{
return ApplyOrder<T>(source, property, "ThenByDescending");
}
static IOrderedQueryable<T> ApplyOrder<T>(IQueryable<T> source, string property, string methodName)
{
string[] props = property.Split('.');
Type type = typeof(T);
ParameterExpression arg = Expression.Parameter(type, "x");
Expression expr = arg;
foreach (string prop in props)
{
PropertyInfo pi = type.GetProperty(prop);
expr = Expression.Property(expr, pi);
type = pi.PropertyType;
}
Type delegateType = typeof(Func<,>).MakeGenericType(typeof(T), type);
LambdaExpression lambda = Expression.Lambda(delegateType, expr, arg);
object result = typeof(Queryable).GetMethods().Single(
method => method.Name == methodName
&& method.IsGenericMethodDefinition
&& method.GetGenericArguments().Length == 2
&& method.GetParameters().Length == 2)
.MakeGenericMethod(typeof(T), type)
.Invoke(null, new object[] { source, lambda });
return (IOrderedQueryable<T>)result;
}
#endregion
}
}
On escalado, throws the exception. It throws with or wihtout Include.
static void Main(string[] args)
{
try
{
using (var context = new CKContext())
{
var servReprosWithIncludes = context.ServicioRepro
.Include(p => p.Categoria)
.ToList();
var escalado = context.EscaladoPrecio
//.Include(p => p.Servicio)
.ToList();
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}
InvalidOperationException: The value of a property that is part of an object's key does not match the corresponding property value stored in the ObjectContext. This can occur if properties that are part of the key return inconsistent or incorrect values or if DetectChanges is not called after changes are made to a property that is part of the key.
The mapping of EscaladoPrecio:
public class EscaladoPrecioMapping : EntityTypeConfiguration<EscaladoPrecio>
{
public EscaladoPrecioMapping()
{
base.HasKey(p => new { p.Desde, p.Hasta, p.ServicioReproId });
base.HasRequired(p => p.Servicio)
.WithMany()
.HasForeignKey(p => p.ServicioReproId);
base.ToTable("PreciosServicioReprografia");
}
}
The entity ServicioRepro is a part from TPT hierarchy. Looks like:
public class ServicioRepro : Producto
{
public bool IncluirPrecioClick { get; set; }
public bool IncluirPrecioPapel { get; set; }
public bool HayPapel { get; set; }
public bool HayImpresion { get; set; }
public bool PrecioPorVolumen { get; set; }
//public virtual ICollection<EscaladoPrecio> EscaladoPrecio { get; set; }
public virtual CategoriaServicioRepro Categoria { get; set; }
public virtual ServicioReproFacturacionType ServicioReproFacturacionType { get; set; }
}
On this entity you can't see the key, because the base entity Producto have it.
The entity EscaladoPrecio have 3 PK: desde, hasta and Servicio. Servicio is PK and FK.
The entity looks like (methods, overrides and members have been removed to reduce the code):
public class EscaladoPrecio : IComparable<EscaladoPrecio>, IComparable<int>, IComparable, IEntity
{
#region Declarations
private int _desde;
private int _hasta;
private double _precio;
private int _cada;
#endregion Declarations
#region Constructor
public EscaladoPrecio()
: this(1, 1, 0, 0)
{ }
public EscaladoPrecio(int desde, int hasta, double precio)
: this(desde, hasta, precio, 0)
{ }
public EscaladoPrecio(int desde, int hasta, double precio, int cada)
{
_desde = desde;
_hasta = hasta;
_precio = precio;
_cada = cada;
}
#endregion Constructor
#region Properties
public int Desde
{
get
{
return _desde;
}
set
{
_desde = value;
}
}
public int Hasta
{
get
{
return _hasta;
}
set
{
_hasta = value;
}
}
public double Precio
{
get
{
return _precio;
}
set
{
_precio = value;
}
}
public int Cada
{
get
{
return _cada;
}
set
{
_cada = value;
}
}
#endregion Properties
private int _ServicioReproId;
public int ServicioReproId
{
get
{
if (Servicio != null)
{
_ServicioReproId = Servicio.Id;
return Servicio.Id;
}
else
return 0;
}
set
{
_ServicioReproId = value;
}
}
public virtual ServicioRepro Servicio { get; set; }
}
Why throws the exception?
Why are you doing this:
public int ServicioReproId
{
get
{
if (Servicio != null)
{
_ServicioReproId = Servicio.Id;
return Servicio.Id;
}
else
return 0;
}
set
{
_ServicioReproId = value;
}
}
Your part of the key property ServicioReproId is returning 0 here potentially although it has been loaded (and stored in the context) with a value != 0 (probably). I think this part of the exception is refering to this problem: "This can occur if properties that are part of the key return inconsistent or incorrect values."
Better leave it an automatic property:
public int ServicioReproId { get; set; }
try to initialice his virtual property in the constructor of the class EscaladoPrecio()