在ABP中AppUser表的数据字段是有限的，现在有个场景是和小程序对接，需要在AppUser表中添加一个OpenId字段。今天有个小伙伴在群中遇到的问题是基于ABP的AppUser对象扩展后，用户查询是没有问题的，但是增加和更新就会报"XXX field is required"的问题。本文以AppUser表扩展OpenId字段为例进行介绍。

一.AppUser实体表

AppUser.cs位于BaseService.Domain项目中，如下：

public class AppUser : FullAuditedAggregateRoot<Guid>, IUser
{
    public virtual Guid? TenantId { get; private set; }
    public virtual string UserName { get; private set; }
    public virtual string Name { get; private set; }
    public virtual string Surname { get; private set; }
    public virtual string Email { get; private set; }
    public virtual bool EmailConfirmed { get; private set; }
    public virtual string PhoneNumber { get; private set; }
    public virtual bool PhoneNumberConfirmed { get; private set; }

    // 微信应用唯一标识
    public string OpenId { get; set; }

    private AppUser()
    {
    }
}

因为AppUser继承自聚合根，而聚合根默认都实现了IHasExtraProperties接口，否则如果想对实体进行扩展，那么需要实体实现IHasExtraProperties接口才行。

二.实体扩展管理

BaseEfCoreEntityExtensionMappings.cs位于BaseService.EntityFrameworkCore项目中，如下：

public class BaseEfCoreEntityExtensionMappings
{
    private static readonly OneTimeRunner OneTimeRunner = new OneTimeRunner();

    public static void Configure()
    {
        BaseServiceModuleExtensionConfigurator.Configure();

        OneTimeRunner.Run(() =>
        {
            ObjectExtensionManager.Instance
                .MapEfCoreProperty<IdentityUser, string>(nameof(AppUser.OpenId), (entityBuilder, propertyBuilder) =>
                    {
                        propertyBuilder.HasMaxLength(128);
                        propertyBuilder.HasDefaultValue("");
                        propertyBuilder.IsRequired();
                    }
                );
        });
    }
}

三.数据库上下文

BaseServiceDbContext.cs位于BaseService.EntityFrameworkCore项目中，如下：

[ConnectionStringName("Default")]
public class BaseServiceDbContext : AbpDbContext<BaseServiceDbContext>
{
    ......
    
    public BaseServiceDbContext(DbContextOptions<BaseServiceDbContext> options): base(options)
    {
    }

    protected override void OnModelCreating(ModelBuilder builder)
    {
        base.OnModelCreating(builder);

        builder.Entity<AppUser>(b =>
        {
            // AbpUsers和IdentityUser共享相同的表
            b.ToTable(AbpIdentityDbProperties.DbTablePrefix + "Users"); 
            
            b.ConfigureByConvention();
            b.ConfigureAbpUser();
            
            b.Property(x => x.OpenId).HasMaxLength(128).HasDefaultValue("").IsRequired().HasColumnName(nameof(AppUser.OpenId));
        });

        builder.ConfigureBaseService();
    }
}

四.数据库迁移和更新

1.数据库迁移

dotnet ef migrations add add_appuser_openid

2.数据库更新

dotnet ef database update

3.对额外属性操作

数据库迁移和更新后，在AbpUsers数据库中就会多出来一个OpenId字段，然后在后端中就可以通过SetProperty或者GetProperty来操作额外属性了：

// 设置额外属性
var user = await _identityUserRepository.GetAsync(userId);
user.SetProperty("Title", "My custom title value!");
await _identityUserRepository.UpdateAsync(user);

// 获取额外属性
var user = await _identityUserRepository.GetAsync(userId);
return user.GetProperty<string>("Title");

但是在前端呢，主要是通过ExtraProperties字段这个json类型来操作额外属性的。

五.应用层增改操作

UserAppService.cs位于BaseService.Application项目中，如下：

1.增加操作

[Authorize(IdentityPermissions.Users.Create)]
public async Task<IdentityUserDto> Create(BaseIdentityUserCreateDto input)
{
    var user = new IdentityUser(
        GuidGenerator.Create(),
        input.UserName,
        input.Email,
        CurrentTenant.Id
    );

    input.MapExtraPropertiesTo(user);

    (await UserManager.CreateAsync(user, input.Password)).CheckErrors();
    await UpdateUserByInput(user, input);

    var dto = ObjectMapper.Map<IdentityUser, IdentityUserDto>(user);

    foreach (var id in input.JobIds)
    {
        await _userJobsRepository.InsertAsync(new UserJob(CurrentTenant.Id, user.Id, id));
    }

    foreach (var id in input.OrganizationIds)
    {
        await _userOrgsRepository.InsertAsync(new UserOrganization(CurrentTenant.Id, user.Id, id));
    }

    await CurrentUnitOfWork.SaveChangesAsync();

    return dto;
}

2.更新操作

[Authorize(IdentityPermissions.Users.Update)]
public async Task<IdentityUserDto> UpdateAsync(Guid id, BaseIdentityUserUpdateDto input)
{
    UserManager.UserValidators.Clear();
    
    var user = await UserManager.GetByIdAsync(id);
    user.ConcurrencyStamp = input.ConcurrencyStamp;

    (await UserManager.SetUserNameAsync(user, input.UserName)).CheckErrors();

    await UpdateUserByInput(user, input);
    input.MapExtraPropertiesTo(user);

    (await UserManager.UpdateAsync(user)).CheckErrors();

    if (!input.Password.IsNullOrEmpty())
    {
        (await UserManager.RemovePasswordAsync(user)).CheckErrors();
        (await UserManager.AddPasswordAsync(user, input.Password)).CheckErrors();
    }

    var dto = ObjectMapper.Map<IdentityUser, IdentityUserDto>(user);
    dto.SetProperty("OpenId", input.ExtraProperties["OpenId"]);
    
    await _userJobsRepository.DeleteAsync(_ => _.UserId == id);

    if (input.JobIds != null)
    {
        foreach (var jid in input.JobIds)
        {
            await _userJobsRepository.InsertAsync(new UserJob(CurrentTenant.Id, id, jid));
        }
    }

    await _userOrgsRepository.DeleteAsync(_ => _.UserId == id);

    if (input.OrganizationIds != null)
    {
        foreach (var oid in input.OrganizationIds)
        {
            await _userOrgsRepository.InsertAsync(new UserOrganization(CurrentTenant.Id, id, oid));
        }
    }

    await CurrentUnitOfWork.SaveChangesAsync();

    return dto;
}

3.UpdateUserByInput()函数

上述增加和更新操作代码中用到的UpdateUserByInput()函数如下：

protected virtual async Task UpdateUserByInput(IdentityUser user, IdentityUserCreateOrUpdateDtoBase input)
{
    if (!string.Equals(user.Email, input.Email, StringComparison.InvariantCultureIgnoreCase))
    {
        (await UserManager.SetEmailAsync(user, input.Email)).CheckErrors();
    }

    if (!string.Equals(user.PhoneNumber, input.PhoneNumber, StringComparison.InvariantCultureIgnoreCase))
    {
        (await UserManager.SetPhoneNumberAsync(user, input.PhoneNumber)).CheckErrors();
    }

    (await UserManager.SetLockoutEnabledAsync(user, input.LockoutEnabled)).CheckErrors();

    user.Name = input.Name;
    user.Surname = input.Surname;
    
    user.SetProperty("OpenId", input.ExtraProperties["OpenId"]);
    
    if (input.RoleNames != null)
    {
        (await UserManager.SetRolesAsync(user, input.RoleNames)).CheckErrors();
    }
}

  实体扩展的好处是不用继承实体，或者修改实体就可以对实体进行扩展，可以说是非常的灵活，但是实体扩展并不适用于复杂的场景，比如使用额外属性创建索引和外键、使用额外属性编写SQL或LINQ等。遇到这种情况该怎么办呢？有种方法是直接引用源码和添加字段。

参考文献：
[1]自定义应用模块：https://docs.abp.io/zh-Hans/abp/6.0/Customizing-Application-Modules-Guide
[2]自定义应用模块-扩展实体：https://docs.abp.io/zh-Hans/abp/6.0/Customizing-Application-Modules-Extending-Entities
[3]自定义应用模块-重写服务：https://docs.abp.io/zh-Hans/abp/6.0/Customizing-Application-Modules-Overriding-Services
[4]ABP-MicroService：https://github.com/WilliamXu96/ABP-MicroService