public class MyData
{
public string Email { get; set; }
public string Password { get; set; }
public string UserId { get; set; }
}
public class MyWorkflow : IWorkflow
{
public void Build(IWorkflowBuilder<MyData> builder)
{
builder
.StartWith<CreateUser>()
.Input(step => step.Email, data => data.Email)
.Input(step => step.Password, data => data.Password)
.Output(data => data.UserId, step => step.UserId)
.Then<SendConfirmationEmail>()
.WaitFor("confirmation", data => data.UserId)
.Then<UpdateUser>()
.Input(step => step.UserId, data => data.UserId);
}
}
https://github.com/danielgerlag/workflow-core
Trying to understand this piece of code above.
Line 13 has StartWith<CreateUser>() but I don't see anywhere CreateUser type being used at all so whats the use of CreateUser?
and also how do i know what is the object step and data in line 14?
For the life of me, I cannot get this to work properly. I have a relatively simple domain model that has a couple of navigation properties that I want to fill out via eager loading.
To keep my domain model pure, I have opted to use shadow properties as foreign keys, so they are not accessible by the client code.
This is the domain model:
public class CourseType : Entity
{
protected CourseType() { }
public CourseType(string name, CoachGroup coachGroup, bool active)
{
Name = name;
CoachGroup = coachGroup;
Active = active;
}
public string Name { get; private set; }
private int? _coachGroupId;
private int? CoachGroupId => _coachGroupId;
public virtual CoachGroup CoachGroup { get; private set; }
public int? AgeLimit { get; private set; }
public bool Active { get; private set; }
public bool ShowInSearchForm { get; private set; }
private List<Course> _accessGivingCourses = new List<Course>();
public virtual IReadOnlyList<Course> AccessGivingCourses => _accessGivingCourses?.ToList();
}
This is how I wire the configuration up:
public class CourseTypeConfiguration : IEntityTypeConfiguration<CourseType>
{
public void Configure(EntityTypeBuilder<CourseType> builder)
{
builder.ToTable("CourseTypes", "Courses");
builder.HasKey(p => p.Id);
builder.Property(p => p.Id).HasColumnName("CourseTypeId");
builder.Property(p => p.Name).HasColumnName("CourseTypeName");
builder.Property(p => p.Active).HasColumnName("IsActive");
builder.Property(p => p.ShowInSearchForm).HasColumnName("ShowInSearchForm");
builder.Property(p => p.AgeLimit).HasColumnName("AgeLimit");
builder.Property<int?>("CoachGroupId").HasField("_coachGroupId");
builder.HasOne(p => p.CoachGroup).WithOne().HasForeignKey<CourseType>("CoachGroupId").OnDelete(DeleteBehavior.Restrict);
builder.HasMany(p => p.AccessGivingCourses).WithMany("AccessGivingCourses")
.UsingEntity<Dictionary<string, object>>("CourseTypesAccessGivingCourses",
j => j.HasOne<Course>().WithMany().HasForeignKey("CourseId"),
j => j.HasOne<CourseType>().WithMany().HasForeignKey("CourseTypeId"),
j => j.ToTable("CourseTypesAccessGivingCourses")
);
builder.HasIndex("CoachGroupId").IsUnique(false);
}
}
This is how I extract the data via my repository class:
public override async Task<IEnumerable<CourseType>> GetAll()
{
try
{
return await Context.CourseTypes.Include(i => i.CoachGroup).Include(i => i.AccessGivingCourses).ToListAsync();
}
catch (Exception e)
{
Logger.LogCritical(e, $"Could not retrieve list of course type entities");
throw;
}
}
It ALMOST works, except for the fact that when I add or update entities, the CoachGroup link randomly gets lost for some updates. For others, it works just fine. It's like Entity Framework Core OR the database randomly loses track of it. Which is odd, because when I look in the database table, the foreign keys in the table are all there like they're supposed to!?
Does anyone have any idea what the hell I am doing wrong? Or if this is the correct approach to this problem at all? All I want to do is to load related data, but it's getting to the point where it's becoming rocket science to merely link a couple of optional relationships together...
I try to use EF core, but only a part of my model is saved to the database.
This is my model:
public class EngineType
{
public string Name { get; set; }
}
public class Car
{
public long CarId { get; set; }
public string Name { get; set; }
public EngineType Engine { get; set; }
}
The CarId and the Name is saved, but not the EngineType.
This is the test I use, but actual.Engine is always null:
[TestMethod]
public void WhenIAddAndSaveANewCarThenItIsAddedToDB()
{
using var target = new EFCoreExampleContext();
using var concurrentContext = new EFCoreExampleContext();
var expected = new Car() {CarId = 0815, Name = "Isetta", Engine = new EngineType() { Name = "2Takt" }};
target.Cars.Add(expected);
target.SaveChanges();
var actual = concurrentContext.Cars.Single();
Assert.AreEqual(1, concurrentContext.Cars.Count());
Assert.IsNotNull(actual.Engine);
Assert.AreEqual(expected, actual);
}
My Context looks like this:
public class EFCoreExampleContext : DbContext
{
public DbSet<Car> Cars { get; set; }
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
optionsBuilder.UseInMemoryDatabase(databaseName: "Add_writes_to_database");
}
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<EngineType>(
d =>
{
d.HasKey(e => e.Name);
d.Property(e => e.Name).IsRequired();
});
modelBuilder.Entity<EngineType>(
d =>
{
d.HasKey(e => e.Name);
});
modelBuilder.Entity<Car>(
d =>
{
d.HasKey(e => e.CarId);
d.Property<DateTime>("LastChanged").IsRowVersion().ValueGeneratedOnAddOrUpdate();
d.Property<string>("EngineForeignKey");
d.HasOne(e => e.Engine)
.WithMany()
.HasForeignKey("EngineForeignKey")
.IsRequired();
});
}
}
Any idea what am I doing wrong (or which existing topic answers this question - I even didn't have the right search words to find it).
Thanks!
I think there is no issue with saving. Entity Framework does not do eager loading by default. So you have to explicitly include any navigational properties that should be in result. Try this when you are fetching actual,
using Microsoft.EntityFrameworkCore;
var actual = concurrentContext.Cars.Include(c => c.Engine).Single();
I am writing a test OData Rest API with an InMemoryDatabase.
I would like to use DTO(s) to hide the SQL model and adjust a few fields (geographic positions and so on).
However, when I use ProjectTo<...> method from AutoMapper, GET request to the API return an empty collection instead of the actual result list.
Do you have any idea about what I am doing wrong ?
Here is the controller :
namespace offers_api.Controllers
{
public class OffersController : ODataController
{
private readonly OfferContext _context;
private IMapper _mapper;
public OffersController(OfferContext context, IMapper mapper)
{
_context = context;
_mapper = mapper;
}
[EnableQuery]
public IActionResult Get()
{
IQueryable<Offer> res = _context.Offers.ProjectTo<Offer>(_mapper.ConfigurationProvider); // <-- works without ProjectTo !
return Ok(res);
}
}
}
The automapper declaration :
namespace offers_api.Entities
{
public class Mapping : Profile
{
public Mapping()
{
//CreateMap<CategoryEntity, string>().ConvertUsing(cat => cat.Name ?? string.Empty);
CreateMap<LocationEntity, Location>()
.ForMember(x => x.longitude, opt => opt.MapFrom(o => 0))
.ForMember(x => x.latitude, opt => opt.MapFrom(o => 0))
.ReverseMap();
CreateMap<OfferEntity, Offer>()
.ForMember(x => x.Category, opt => opt.MapFrom(o => o.Category.Name))
.ReverseMap()
.ForMember(x => x.Category, opt => opt.MapFrom(o => new CategoryEntity { Name = o.Category }));
CreateMap<OfferPictureEntity, OfferPicture>().ReverseMap();
CreateMap<UserEntity, User>().ReverseMap();
}
}
}
The EDM model :
private static IEdmModel GetEdmModel()
{
ODataConventionModelBuilder builder = new ODataConventionModelBuilder();
builder.EntitySet<Offer>("Offers");
return builder.GetEdmModel();
}
I found the solution.
In fact, automapper loaded more data than OData's default behaviour.
The relation between an offer and it's author was described by a non nullable foreing key. I didn't insert any author in the DB, but OData tried to load a user and saw it was missing in the USER table, so it discarded the Offer result.
Solution : make the foreign key nullable.
namespace offers_api.Entities
{
public class OfferEntity
{
[Key]
public long Id { get; set; }
public string Title { get; set; }
public string Description { get; set; }
public long AuthorId { get; set; } // <== Bug here : add long? to resolve it...
public virtual UserEntity Author { get; set; }
}
}
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.