I'm using EF Core and have the following project structure

AppName.Entity

• Alert
• Other classes

AppName.Repository

• AlertRepository
• Other Repository classes

The alert entity is as follows:

using System;
using System.ComponentModel.DataAnnotations;

namespace AppName.Entity
{
    public class Alert
    {
        [Key]
        public int AlertId { get; set; }
        public string RuleId { get; set; }
        public string DeviceId { get; set; }
        public string VehicleVin { get; set; }
        public string AlertText { get; set; }
        public DateTime DateTimeUtc { get; set; }
        public AlertCategory AlertCategory { get; set; }
    }

    public enum AlertCategory
    {
        VehicleHealth = 1,
        FleetHealth = 2,
        EmissionsHealth = 3,
        Fuel = 4,
        AssetUtilization = 5,
        Safety = 6,
        DutyCycle = 7
    }
}

AlertRepository.cs is as follows:

using AppName.Entity;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace AppName.Repository
{
    public class AlertRepository//  : GenericRepository<Alert>, IAlertRepository
    {
        public async Task<int> Save(Alert alert)
        {
            using (AFIdbContext context = new AFIdbContext())
            {
                context.Alerts.Add(alert);
                await context.SaveChangesAsync();
                return alert.AlertId;
            }
        }

        public async Task<bool> Save(IEnumerable<Alert> alerts)
        {
            using (AFIdbContext context = new AFIdbContext())
            {
                foreach (Alert alert in alerts)
                {
                    context.Alerts.Add(alert);
                }

                await context.SaveChangesAsync();

                return true;
            }
        }

        public IQueryable<Alert> GetList(DateTime fromDate, DateTime toDate, int pageSize, int pageNum)
        {
            using (AFIdbContext context = new AFIdbContext())
                return context.Alerts.Where(x => x.DateTimeUtc >= fromDate && x.DateTimeUtc <= toDate).Skip(pageSize * pageNum).Take(pageSize);
        }
    }
}

AFIdbContext.cs

using AppName.Entity;
using Microsoft.EntityFrameworkCore;
using System.Configuration;

namespace AppName.Repository
{
    public class AFIdbContext : DbContext
    {

        private string _afiConnstring;

        public string AFIConnstring
        {
            get 
            {
                if (_afiConnstring != null)
                    return _afiConnstring;
                else
                    return "";

            }

        }



        public AFIdbContext() : base()
        {

        }


        public AFIdbContext(DbContextOptions<AFIdbContext> options) : base(options)
        {

        }

        public DbSet<Alert> Alerts { get; set; }
        public DbSet<User> Users { get; set; }
        public DbSet<UserAlertPreference> UserAlertPreferences { get; set; }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.Entity<AlertRepository>().ToTable("Alert");
            modelBuilder.Entity<User>().ToTable("User");
            modelBuilder.Entity<UserAlertPreference>().ToTable("UserAlertPreference");
        }

        protected override void OnConfiguring(DbContextOptionsBuilder options)
        {
            options.UseSqlServer(AppExtensions.ConnString);
        }
    }
}

When I attempt to save a collection of Alerts, I get the following exception:

System.InvalidOperationException: 'The entity type 'AlertRepository' requires a primary key to be defined. If you intended to use a keyless entity type call 'HasNoKey()'.'

The Alert entity does have a primary key in the DB and does have the [Key] attribute. Why is it telling me that the AlertRepository object doesn't have the key set when it's an Alert Entity I am trying to save? Can I not have the Entity in a separate project? I'm trying to follow a DDD pattern

The exception is being thrown before it even tries to save the records

(I have a breakpoint on await context.SaveChangesAsync(); in AlertRepository

The solution here doesn't help because I already have those set

CodePudding user response：

You have mapped the wrong entity in your OnModelCreating for table Alert.

Try with

modelBuilder.Entity<Alert>().ToTable("Alert")

CodePudding user response：

AlertRepository is not right class to be an entity, you just have to map the Alert entity in OnModelCreating

Replace

modelBuilder.Entity().ToTable("Alert");

with

modelBuilder.Entity().ToTable("Alert")

or you can just remove this line because entity framework will create a table for you with same name as your entity.