WPF应用执行update-database时遇SQLite错误：无__EFMigrationsHistory表

执行add-migration Initial可正常生成迁移文件，但运行update-database时触发错误：

SQLite Error 1: 'no such table: __EFMigrationsHistory'

相关代码如下：

namespace ToDoListApp.Data;
public class ApplicationDbContext : DbContext
{
    private readonly string _connectionString = ConfigurationManager.AppSettings["Database"];
    public DbSet<Task> Tasks { get; set; }

    public ApplicationDbContext(DbContextOptions options) : base(options)
    {

    }

    public ApplicationDbContext()
    {

    }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.ApplyConfiguration(new TasksConfiguration());
    }
}

namespace ToDoListApp.Data;
public class ApplicationDesignTimeDbContextFactory : IDesignTimeDbContextFactory<ApplicationDbContext>
{
    private readonly string _connectionString = ConfigurationManager.AppSettings["Database"];

    public ApplicationDbContext CreateDbContext(string[] args)
    {
        var options = new DbContextOptionsBuilder().UseSqlite(_connectionString).Options;

        return new ApplicationDbContext(options);
    }
}

public class TasksConfiguration : IEntityTypeConfiguration<Task>
{
    public void Configure(EntityTypeBuilder<Task> builder)
    {
        builder.HasKey(t => t.Id);

        builder.Property(t => t.Title)
            .HasMaxLength(35)
            .IsRequired();

        builder.Property(t => t.Description)
            .HasMaxLength(200)
            .IsRequired();
    }
}

namespace ToDoListApp;
/// <summary>
/// Interaction logic for App.xaml
/// </summary>
public partial class App : Application
{
    private IServiceProvider _serviceProvider;
    private string _connectionString = @ConfigurationManager.AppSettings["Database"];

    public App()
    {
        ConfigureServices();
    }

    private void ConfigureServices()
    {
        var services = new ServiceCollection();

        services.AddSingleton<TaskWindow>();
        services.AddDbContext<ApplicationDbContext>(options => options.UseSqlite(_connectionString));
        services.AddScoped<IRepository<Task>, TaskRepositoryDatabase>();
        services.AddScoped<IService<Task>, TaskService>();
        services.AddScoped<TaskViewModel>();

        _serviceProvider = services.BuildServiceProvider();
    }

    protected override void OnStartup(StartupEventArgs e)
    {
        var taskWindow = _serviceProvider.GetRequiredService<TaskWindow>();
        taskWindow.DataContext = _serviceProvider.GetRequiredService<TaskViewModel>();

        taskWindow.Show();

        base.OnStartup(e);
    }
}

解决方案 #

1. 修复ApplicationDbContext无参构造函数的连接配置 #

你的ApplicationDbContext存在无参构造函数，但未配置SQLite连接字符串。EF Core执行update-database时可能优先使用该构造函数，导致连接到默认空SQLite数据库，无法找到__EFMigrationsHistory表。修改无参构造函数：

public ApplicationDbContext() : base(GetOptions())
{
}

private static DbContextOptions<ApplicationDbContext> GetOptions()
{
    var connectionString = ConfigurationManager.AppSettings["Database"];
    return new DbContextOptionsBuilder<ApplicationDbContext>()
        .UseSqlite(connectionString)
        .Options;
}

2. 修正DesignTimeDbContextFactory的泛型配置 #

使用泛型DbContextOptionsBuilder<ApplicationDbContext>替代非泛型版本，避免上下文配置不一致：

public ApplicationDbContext CreateDbContext(string[] args)
{
    var connectionString = ConfigurationManager.AppSettings["Database"];
    var options = new DbContextOptionsBuilder<ApplicationDbContext>()
        .UseSqlite(connectionString)
        .Options;

    return new ApplicationDbContext(options);
}

3. 重置迁移状态（可选） #

若之前的迁移已处于异常状态，可执行以下步骤重置：

• 删除项目中Migrations文件夹的所有文件
• 删除本地SQLite数据库文件（如.db格式文件）
• 重新执行命令：

  add-migration Initial
  update-database
  

4. 验证连接字符串有效性 #

确认ConfigurationManager.AppSettings["Database"]读取到的是正确格式的SQLite连接字符串，示例格式：

Data Source=ToDoList.db;

可在ApplicationDesignTimeDbContextFactory中添加日志输出验证：

public ApplicationDbContext CreateDbContext(string[] args)
{
    Console.WriteLine($"当前连接字符串：{_connectionString}");
    // 原有代码...
}

内容的提问来源于stack exchange，提问作者tudoooor