Question

我正在尝试为项目创建新的迁移，但我不断得到：

建立与SQL Server的连接时发生与网络相关或特定于实例的错误。服务器未找到或无法访问。验证实例名称正确，并且已将SQL Server配置为允许远程连接。（提供者：SQL网络接口，错误：26-指定服务器/实例时出错）

我在appsettings.json中有连接字符串：

  "ConnectionStrings": {
    "DefaultConnection": "Server=xx.xx.xxx.206;Database=AngularASPNETCore2WebApiAuth; User ID = me; Password= not_pwd;Trusted_Connection=False;MultipleActiveResultSets=true"
  },

我尝试过：

确认连接字符串正确（它在具有不同数据库名称的另一个项目中有效）
确认可以使用conn字符串中提供的凭据登录SQL
在初始迁移中从Up方法中删除所有内容，然后重新运行update-database命令。（结果相同）

我还能尝试解决什么问题？

在Startup.cs内部进行连接的呼叫：

public void ConfigureServices(IServiceCollection services)
{
  // Add framework services.
  services.AddDbContext<ApplicationDbContext>(options =>
      options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection"),
          b => b.MigrationsAssembly("AngularASPNETCore2WebApiAuth")
          ));

  services.AddSingleton<IJwtFactory, JwtFactory>();

  // Register the ConfigurationBuilder instance of FacebookAuthSettings
  services.Configure<FacebookAuthSettings>(Configuration.GetSection(nameof(FacebookAuthSettings)));

  services.TryAddTransient<IHttpContextAccessor, HttpContextAccessor>();

  // jwt wire up
  // Get options from app settings
  var jwtAppSettingOptions = Configuration.GetSection(nameof(JwtIssuerOptions));

  // Configure JwtIssuerOptions
  services.Configure<JwtIssuerOptions>(options =>
  {
    options.Issuer = jwtAppSettingOptions[nameof(JwtIssuerOptions.Issuer)];
    options.Audience = jwtAppSettingOptions[nameof(JwtIssuerOptions.Audience)];
    options.SigningCredentials = new SigningCredentials(_signingKey, SecurityAlgorithms.HmacSha256);
  });

  var tokenValidationParameters = new TokenValidationParameters
  {
    ValidateIssuer = true,
    ValidIssuer = jwtAppSettingOptions[nameof(JwtIssuerOptions.Issuer)],

    ValidateAudience = true,
    ValidAudience = jwtAppSettingOptions[nameof(JwtIssuerOptions.Audience)],

    ValidateIssuerSigningKey = true,
    IssuerSigningKey = _signingKey,

    RequireExpirationTime = false,
    ValidateLifetime = true,
    ClockSkew = TimeSpan.Zero
  };

  services.AddAuthentication(options =>
  {
    options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
    options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;

  }).AddJwtBearer(configureOptions =>
  {
    configureOptions.ClaimsIssuer = jwtAppSettingOptions[nameof(JwtIssuerOptions.Issuer)];
    configureOptions.TokenValidationParameters = tokenValidationParameters;
    configureOptions.SaveToken = true;
  });

  // api user claim policy
  services.AddAuthorization(options =>
  {
    options.AddPolicy("ApiUser", policy => policy.RequireClaim(Constants.Strings.JwtClaimIdentifiers.Rol, Constants.Strings.JwtClaims.ApiAccess));
    });

  // add identity
  var builder = services.AddIdentityCore<AppUser>(o =>
  {
          // configure identity options
          o.Password.RequireDigit = false;
    o.Password.RequireLowercase = false;
    o.Password.RequireUppercase = false;
    o.Password.RequireNonAlphanumeric = false;
    o.Password.RequiredLength = 6;
  });
  builder = new IdentityBuilder(builder.UserType, typeof(IdentityRole), builder.Services);
  builder.AddEntityFrameworkStores<ApplicationDbContext>().AddDefaultTokenProviders();

  services.AddAutoMapper();
  services.AddMvc().AddFluentValidation(fv => fv.RegisterValidatorsFromAssemblyContaining<Startup>());
}

Answer 1

通常可以通过以下方法解决此错误：

确保SQL Server服务正在运行
确保已将sql服务器配置为允许远程连接。
如果是命名实例，请确保SQL Server浏览器服务正在运行
检查SQL Server错误日志中是否有消息，确认SQL正在侦听预期的网络接口和端口（例如：1433）
检查以查看web.config或端口正确的情况下连接的编码位置。
检查防火墙设置-在防火墙中为端口添加例外

这篇文章非常有用，并提供了详细的信息：

Why am I getting "Cannot Connect to Server - A network-related or instance-specific error"?

This question上的

Database Administrators有一些好的建议。

SQL Server找不到服务器或无法访问服务器

1 个答案: