Question

我正在使用新的ASP.NET 5 beta 8，当我有两个dbcontext时遇到麻烦。

我有以下项目结构。

-Data(Identity 3 db with other entities)
-Resources (Contains a db with translations)
-WebApp

在WebApp

中的Startup.cs中删除了一些代码

 public void ConfigureServices(IServiceCollection services)
 {
        services.AddEntityFramework()
            .AddSqlServer()
            .AddDbContext<DatabaseContext>(opt => opt.UseSqlServer(Configuration["Data:MainDb:ConnectionString"]));

        services.AddIdentity<ApplicationUser, IdentityRole>()
            .AddEntityFrameworkStores<DatabaseContext>()
            .AddDefaultTokenProviders();

        services.AddEntityFramework()
            .AddSqlServer()
            .AddDbContext<ResourceDbContext>(opt => opt.UseSqlServer(Configuration["Data:Resources:ConnectionString"]));

        services.AddTransient<IResourceDbContext, ResourceDbContext>();
        services.AddTransient<IDatabaseContext, DatabaseContext>();
}

在ResourceDbContext和DatabaseContext中，我执行以下操作

    public ResourceDbContext(DbContextOptions options) : base(options)
    {
        _connectionString = ((SqlServerOptionsExtension)options.Extensions.First()).ConnectionString;
    }


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

但是，当我从appsettings.json读取连接字符串时，我在ConfigureServices中收到了正确的值。但是DbContextOptions只包含最新加载的值，在本例中是Resources的连接字符串。所以dbcontext都建立了与Resource db的连接。

我无法找到有关此内容的任何信息。

Answer 1

您需要做的就是表明DbContextOptions是泛型类型：

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

}

现在，依赖注入系统可以在创建ResourceDbContext并将其注入构造函数时找到正确的依赖项（DbContextOptions options）。

See implementation AddDbContext method

Miroslav Siska：

public class GetHabitsIdentity: IdentityDbContext<GetHabitsUser, IdentityRole, string> where TUser : IdentityUser
{
    public GetHabitsIdentity(DbContextOptions<GetHabitsIdentity> options)
        :base(options)
    {

    }        
}

Answer 2

您可以将EF与不同的连接字符串一起使用。我没有在你的代码中看到错误。我使用了这个设置。

services.AddEntityFramework()
            .AddSqlServer()
            .AddDbContext<ApplicationDbContext>(options =>
                options.UseSqlServer(Configuration["Data:DefaultConnection:ConnectionString"]));
        services.AddEntityFramework()
            .AddSqlServer()
            .AddDbContext<ApplicationContext>(options =>
                options.UseSqlServer(Configuration["Data:OtherConnection:ConnectionString"]));

在DBContext类中

public class ApplicationDbContext : IdentityDbContext<ApplicationUser>
{
    public DbSet<Localizations> Localizations { get; set; }
    private string _connectionString;

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        _connectionString = ((SqlServerOptionsExtension)optionsBuilder.Options.Extensions.First()).ConnectionString;
        Console.WriteLine($"ApplicationDbContext{_connectionString}");
    }


public class ApplicationContext : DbContext
{
    private string _connectionString;

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        _connectionString = ((SqlServerOptionsExtension)optionsBuilder.Options.Extensions.First()).ConnectionString;
        Console.WriteLine($"ApplicationContext{_connectionString}");
    }
}

Answer 3

感谢您的大力帮助!!!

完整的解决方案：

  public class TenantDbContext : IdentityDbContext<ApplicationUser, IdentityRole, string>
{
    private string _connectionString { get; set; }  

    public TenantDbContext(DbContextOptions<TenantDbContext> options) : base(options)  
    {
        this._connectionString = "Connection String";
    }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    { 
        optionsBuilder.UseSqlServer(_connectionString); 
    }
}

ASP.NET 5 DI用于将DbContext和UserManager注入控制器。现在可以登录并注册多个数据库......现在我只需要检查如何在这里注入连接字符串：this._connectionString =“Connection String”;但这很简单......再次感谢你！

ASP.NET 5多个dbcontext问题

3 个答案: