dbcontext

问题 Using the fluent api, how do I map a custom type as the primary key within my OnModelCreating method of the DbContext class? Using EF Core I'm trying to build a model for the follow entity. public class Account { public AccountId AccountId { get; } public string Name { get; set; } private Account() { } public Account(AccountId accountId, string name) { AccountId = accountId; Name = name; } } Where the primary key is the AccountId ; the type is a simple value object like this. public class

问题 I am trying to implement all sorts of good stuff like UnitOfWork, Repository, DI. I am using Unity for DI. Here is my dilemma. I have a few (currently 3) databases with identical schema but obviously with different data for business reasons (I will call them GroupDB1, GroupDB2 and GroupDB3). I also have a Master Database (DifferentDB) that has a different schema. My dbcontext need to use different databases for different scenarios at runtime. I have no clue how to put them all to work

问题 For third party authentication, I need a custom Authorize attribute. Here a repository ( SessionManager ) class is required to check if the user is logged in. [AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = true, Inherited = true)] public class VBAuthorizeAttribute : AuthorizeAttribute, IAuthorizationFilter { public async void OnAuthorization(AuthorizationFilterContext context) { var sessionManager = (VBSessionManager)context.HttpContext.RequestServices

问题 Here is the code: using (TransactionScope scope = new TransactionScope(TransactionScopeOption.RequiresNew)) { DBContext.AddtoSomeTable(record); System.Threading.Thread.Sleep(5000); DBContext.SaveChanges(); MAX_ID = (from t in DBContext.SomeTable select t.ID).Max(); scope.Complete(); } As far as I know, before the scope is completed, the MAX_ID should be the new record's ID, which is just inserted. Even if there are two users submitting at the same time, the later one should wait until the

问题 I have some POCO classes which can generally divided into two groups, for example: public class Student { public Student() { this.Courses = new List<Course>(); this.Clubs = new List<Club>(); } public int Id { get; set; } public virtual ICollection<Course> Courses { get; set; } public virtual ICollection<Club> Clubs { get; set; } } and corresponding Course and Club classes, and they all have their own relationships to other classes. The problem is, those two groups are big, they both contains

问题 I am trying to make an interface out of ApplicationDbContext which extends IdentityDbContext. public class ApplicationDbContext : IdentityDbContext<ApplicationUser>, IApplicationDbContext { public ApplicationDbContext() : base("AppContext") { } // Should I add below line? without any unwanted behavior? // public DbSet<ApplicationUser> User { get; set;} public DbSet<Book> Books { get; set; } } My interface will be public interface IApplicationDbContext : IDisposable { // Should I add below

问题 I have the following method in a generic base class: public virtual void Insert(TEntity entity) { dbSet.Add(entity); } My service layer uses the Insert method to add new records. Now I would like to be able to return a bool, to make sure that it inserted properly. Something like the following: public virtual int Count { get { return dbSet.Count(); } } public virtual bool Insert(TEntity entity) { int count = this.Count; dbSet.Add(entity); return this.Count == count + 1; } Is there a more

问题 So I have code pseudo-similar to (dependency injected): public DbContextA DBA { get; set; } // SQL Server 1 public DbContextB DBB { get; set; } // SQL Server 2 I'm just now sure how I can most effectively do the following? public Task<ActionResult> MyAction() { var trucks = await DBA.GetTrucksAsync(); var cars = DBA.GetCarsAsync(); var cats = await DBB.GetCatsAsync(); var dogs = DBB.GetDogsAsync(); await TaskEx.WhenAll(cars, dogs); } Unless I'm mistaken this isn't optimal. I think it would be

问题 This seems like I'm missing a simple detail, I just can't figure out what. Having this string deleteTrigger = "IF OBJECT_ID('@p0') IS NOT NULL " + "DROP TRIGGER [@p1] "; string createTrigger = "CREATE TRIGGER [@p0] " + "ON [dbo].[@p1] " + "AFTER DELETE AS " + "BEGIN " + "SET NoCount ON " + "DELETE FROM [dbo].[MyTable] WHERE ID IN (SELECT ID FROM DELETED) " + "END "; object[] parameterList = new object[] {"Tr_SomeTable_AD", "Tr_SomeTable_AD" }; context.Database.ExecuteSqlCommand(deleteTrigger

问题 I am new in .net core. I am adding migration in .net core Liabrary project in web API core 1.1. using below code. Add-Migration example1 But it's showing below error: 回答1: If you are using VS Code or other editor: In dotnet command cli type: dotnet ef migrations add InitialCreate obs:InitialCreate is the name of migration, you can give any name. If you are using Visual Studio: Create your database Once you have a model, you can use migrations to create a database. Open the PMC: Tools –> NuGet