知道为啥我的 DbInitializer 中的数据没有填充到我的数据库中
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【中文标题】知道为啥我的 DbInitializer 中的数据没有填充到我的数据库中【英文标题】：Any idea why the data in my DbInitializer is not populating in my database知道为什么我的 DbInitializer 中的数据没有填充到我的数据库中 【发布时间】：2021-12-20 18:04:56 【问题描述】：使用 SQL Server Express LocalDB，我在 DbInitializer 中编码的数据不会填充到我的数据库中。我不确定是延迟加载还是缺少某些内容导致数据无法播种。
ApplicationDbContext.cs：
using Microsoft.AspNetCore.Identity.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.Text;
using FinesJune.Models;
namespace FinesJune.Data
public class ApplicationDbContext : IdentityDbContext
public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options)
: base(options)
// The Fines table
public DbSet<Fine> Fines get; set;
protected override void OnModelCreating(ModelBuilder builder)
base.OnModelCreating(builder);
这是我的DbInitializer 课程，其中数据被写入以在播种时编码到数据库中：
using FinesJune.Models;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Identity.EntityFrameworkCore;
using Microsoft.AspNetCore.Identity;
using Microsoft.Extensions.DependencyInjection;
namespace FinesJune.Data
public static class DbInitializer
public static void Seed(ApplicationDbContext context, IServiceProvider services)
// Seed roles
// Get the Identity Role Manager from services
RoleManager<IdentityRole> roleManager = services.GetRequiredService<RoleManager<IdentityRole>>();
// Create each role
roleManager.CreateAsync(new IdentityRole() Name = "Traffic Manager" ).Wait();
roleManager.CreateAsync(new IdentityRole() Name = "Traffic Officer" ).Wait();
roleManager.CreateAsync(new IdentityRole() Name = "Driver" ).Wait();
// Add the test users (one for each role). Employs the usermanager service.
// Driver test user
UserManager<IdentityUser> userManager = services.GetRequiredService<UserManager<IdentityUser>>();
userManager.CreateAsync(new IdentityUser()
Email = "driver@testwebsite.com",
UserName = "driver@testwebsite.com",
EmailConfirmed = true,
TwoFactorEnabled = false
).Wait();
// Get the user from the DB
IdentityUser driverUser = userManager.Users.FirstOrDefault(c => c.Email == "driver@testwebsite.com");
// Give it a password and the appropriate role
userManager.AddPasswordAsync(driverUser, "Pa$$word1").Wait();
userManager.AddToRoleAsync(driverUser, "Driver").Wait();
// Officer test user
userManager.CreateAsync(new IdentityUser()
Email = "officer@testwebsite.com",
UserName = "officer@testwebsite.com",
EmailConfirmed = true,
TwoFactorEnabled = false
).Wait();
// Get the user from the DB
IdentityUser officerUser = userManager.Users.FirstOrDefault(c => c.Email == "officer@testwebsite.com");
// Give it a password and the appropriate role
userManager.AddPasswordAsync(officerUser, "Pa$$word1").Wait();
userManager.AddToRoleAsync(officerUser, "Traffic Officer").Wait();
// Manager test user
userManager.CreateAsync(new IdentityUser()
Email = "manager@testwebsite.com",
UserName = "manager@testwebsite.com",
EmailConfirmed = true,
TwoFactorEnabled = false
).Wait();
// Get the user from the DB
IdentityUser managerUser = userManager.Users.FirstOrDefault(c => c.Email == "manager@testwebsite.com");
// Give it a password and the appropriate role
userManager.AddPasswordAsync(managerUser, "Pa$$word1").Wait();
userManager.AddToRoleAsync(managerUser, "Traffic Manager").Wait();
// Seed fines
var fine = new Fine[]
new Fine
FineID = Guid.NewGuid().ToString(),
OfficerID = Guid.NewGuid().ToString(),
DriverID = Guid.NewGuid().ToString(),
LicensePlate = "CY4345",
VehicleType = VehicleType.Car,
Offense = OffenseType.Speeding,
OffenseDetail = "85km/h in a 60 zone.",
OffenseDate = DateTime.Parse("2017-08-10"),
OffenseTime = DateTime.Parse("05:50"),
Amount = 50.50m,
Outstanding = true
,
new Fine
FineID = Guid.NewGuid().ToString(),
OfficerID = Guid.NewGuid().ToString(),
DriverID = Guid.NewGuid().ToString(),
LicensePlate = "CA323566",
VehicleType = VehicleType.Bus,
Offense = OffenseType.Parking,
OffenseDetail = "Parked on red line.",
OffenseDate = DateTime.Parse("2018-01-20"),
OffenseTime = DateTime.Parse("16:20"),
Amount = 350.00m,
Outstanding = true
,
new Fine
FineID = Guid.NewGuid().ToString(),
OfficerID = Guid.NewGuid().ToString(),
DriverID = Guid.NewGuid().ToString(),
LicensePlate = "CY198450",
VehicleType = VehicleType.Car,
Offense = OffenseType.Speeding,
OffenseDetail = "140km/h in a 100 zone.",
OffenseDate = DateTime.Parse("2014-03-12"),
OffenseTime = DateTime.Parse("09:15"),
Amount = 500.00m,
Outstanding = true
,
new Fine
FineID = Guid.NewGuid().ToString(),
OfficerID = Guid.NewGuid().ToString(),
DriverID = Guid.NewGuid().ToString(),
LicensePlate = "CA321",
VehicleType = VehicleType.Motorcycle,
Offense = OffenseType.Speeding,
OffenseDetail = "65km/h in a 40 zone.",
OffenseDate = DateTime.Parse("2018-10-19"),
OffenseTime = DateTime.Parse("15:00"),
Amount = 250.00m,
Outstanding = true
,
new Fine
FineID = Guid.NewGuid().ToString(),
OfficerID = Guid.NewGuid().ToString(),
DriverID = Guid.NewGuid().ToString(),
LicensePlate = "CA974039",
VehicleType = VehicleType.Car,
Offense = OffenseType.DUI,
OffenseDetail = "DUI of alcohol.",
OffenseDate = DateTime.Parse("2016-11-11"),
OffenseTime = DateTime.Parse("10:10"),
Amount = 650.80m,
Outstanding = false
,
new Fine
FineID = Guid.NewGuid().ToString(),
OfficerID = Guid.NewGuid().ToString(),
DriverID = Guid.NewGuid().ToString(),
LicensePlate = "CY936503",
VehicleType = VehicleType.Car,
Offense = OffenseType.Parking,
OffenseDetail = "Illegally parked on corner.",
OffenseDate = DateTime.Parse("2015-06-21"),
OffenseTime = DateTime.Parse("11:41"),
Amount = 250.00m,
Outstanding = true
,
new Fine
FineID = Guid.NewGuid().ToString(),
OfficerID = Guid.NewGuid().ToString(),
DriverID = Guid.NewGuid().ToString(),
LicensePlate = "CA99840",
VehicleType = VehicleType.Truck,
Offense = OffenseType.Speeding,
OffenseDetail = "100km/h in a 60 zone.",
OffenseDate = DateTime.Parse("2016-06-21"),
OffenseTime = DateTime.Parse("09:55"),
Amount = 1500.00m,
Outstanding = true
,
;
// Add fines into the in-memory context, then save that context's changes into the DB
foreach (Fine f in fine)
context.Fines.Add(f);
context.SaveChanges();
Program.cs
using FinesJune.Data;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
namespace FinesJune
public class Program
public static void Main(string[] args)
var host = CreateHostBuilder(args).Build();
// Set the service scope
var services = host.Services.CreateScope().ServiceProvider;
/* Will run if the context has not yet been created, meaning data is seeded only once.
* Add an '!' to the boolean of this if statement to force a rerun. */
if (services.GetRequiredService<ApplicationDbContext>()
.Database.EnsureCreated())
CreateDbIfNotExists(host);
// Run the host...
host.Run();
private static void CreateDbIfNotExists(IHost host)
using (var scope = host.Services.CreateScope())
var services = scope.ServiceProvider;
try
// Get the context and send it into the DB seed method
var context = services.GetRequiredService<ApplicationDbContext>();
DbInitializer.Seed(context, services);
catch (Exception ex)
var logger = services.GetRequiredService<ILogger<Program>>();
logger.LogError(ex, "An error occurred creating the DB.");
public static IHostBuilder CreateHostBuilder(string[] args) =>
Host.CreateDefaultBuilder(args)
.ConfigureWebHostDefaults(webBuilder =>
webBuilder.UseStartup<Startup>();
);
Startup.cs
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.HttpsPolicy;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Identity.UI;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using FinesJune.Data;
namespace FinesJune
public class Startup
public Startup(IConfiguration configuration)
Configuration = configuration;
public IConfiguration Configuration get;
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
services.AddDbContext<ApplicationDbContext>(options =>
options.UseSqlServer(
Configuration.GetConnectionString("DefaultConnection")));
services.AddDatabaseDeveloperPageExceptionFilter();
// Note that the .AddRoles<IdentityRole>() method is used here to ensure the rolemanager is available in services.
services.AddDefaultIdentity<IdentityUser>(options => options.SignIn.RequireConfirmedAccount = true)
.AddRoles<IdentityRole>()
.AddEntityFrameworkStores<ApplicationDbContext>();
services.AddControllersWithViews();
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
if (env.IsDevelopment())
app.UseDeveloperExceptionPage();
app.UseMigrationsEndPoint();
else
app.UseExceptionHandler("/Home/Error");
// The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
app.UseHsts();
app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseRouting();
app.UseAuthentication();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
endpoints.MapControllerRoute(
name: "default",
pattern: "controller=Home/action=Index/id?");
endpoints.MapRazorPages();
);
我已尝试重新构建、重新启动和运行 Web 应用程序，但数据库没有使用 DbInitializer 中定义的数据作为种子。
编辑：我发现将DbInitializer中的代码添加到Home Controller中的Index方法中，数据被播种到了数据库中
【问题讨论】：
好吧，做一些基本的调试。那里有很好的种子方法。它曾经被调用过吗？你知道，在我们花时间调试之前，我们会有点期待。只需一个不错的小断言或断点，您就知道了。 【参考方案1】：希望以下网址对您有所帮助。
Seed data EF core
【讨论】：
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