使用EF6简实现多租户的应用

2019 年 10 月 3 日
笔记

什么是多租户

网上有好多解释，有些上升到了架构设计，让你觉得似乎非常高深莫测，特别是目前流行的ABP架构中就有提到多租户（IMustHaveTenant），其实说的简单一点就是再每一张数据库的表中添加一个TenantId的字段，用于区分属于不同的租户（或是说不同的用户组）的数据。关键是现实的方式必须对开发人员来说是透明的，不需要关注这个字段的信息，由后台或是封装在基类中实现数据的筛选和更新。

基本原理

从新用户注册时就必须指定用户的TenantId,我的例子是用CompanyId,公司信息做为TenantId,哪些用户属于不同的公司，每个用户将来只能修改和查询属于本公司的数据。

接下来就是用户登录的时候获取用户信息的时候把TenantId保存起来，asp.net mvc（不是 core）是通过 Identity 2.0实现的认证和授权，这里需要重写部分代码来实现。

最后用户对数据查询/修改/新增时把用户信息中TenantId，这里就需要设定一个Filter(过滤器)和每次SaveChange的插入TenantId

如何实现

第一步，扩展 Asp.net Identity user 属性，必须新增一个TenantId字段,根据Asp.net Mvc 自带的项目模板修改IdentityModels.cs 这个文件

 1   // You can add profile data for the user by adding more properties to your ApplicationUser class, please visit http://go.microsoft.com/fwlink/?LinkID=317594 to learn more.   2   public class ApplicationUser : IdentityUser   3   {   4     public async Task<ClaimsIdentity> GenerateUserIdentityAsync(UserManager<ApplicationUser> manager, string authenticationType)   5     {   6       // Note the authenticationType must match the one defined in CookieAuthenticationOptions.AuthenticationType   7       var userIdentity = await manager.CreateIdentityAsync(this, authenticationType);   8       // Add custom user claims here   9       userIdentity.AddClaim(new Claim("http://schemas.microsoft.com/identity/claims/tenantid", this.TenantId.ToString()));  10       userIdentity.AddClaim(new Claim("CompanyName", this.CompanyName));  11       userIdentity.AddClaim(new Claim("EnabledChat", this.EnabledChat.ToString()));  12       userIdentity.AddClaim(new Claim("FullName", this.FullName));  13       userIdentity.AddClaim(new Claim("AvatarsX50", this.AvatarsX50));  14       userIdentity.AddClaim(new Claim("AvatarsX120", this.AvatarsX120));  15       return userIdentity;  16     }  17     public async Task<ClaimsIdentity> GenerateUserIdentityAsync(UserManager<ApplicationUser> manager)  18     {  19       // Note the authenticationType must match the one defined in CookieAuthenticationOptions.AuthenticationType  20       var userIdentity = await manager.CreateIdentityAsync(this, DefaultAuthenticationTypes.ApplicationCookie);  21       // Add custom user claims here  22       return userIdentity;  23     }  24  25     [Display(Name = "全名")]  26     public string FullName { get; set; }  27     [Display(Name = "性别")]  28     public int Gender { get; set; }  29     public int AccountType { get; set; }  30     [Display(Name = "所属公司")]  31     public string CompanyCode { get; set; }  32     [Display(Name = "公司名称")]  33     public string CompanyName { get; set; }  34     [Display(Name = "是否在线")]  35     public bool IsOnline { get; set; }  36     [Display(Name = "是否开启聊天功能")]  37     public bool EnabledChat { get; set; }  38     [Display(Name = "小头像")]  39     public string AvatarsX50 { get; set; }  40     [Display(Name = "大头像")]  41     public string AvatarsX120 { get; set; }  42     [Display(Name = "租户ID")]  43     public int TenantId { get; set; }  44   }  45  46  47  48   public class ApplicationDbContext : IdentityDbContext<ApplicationUser>  49   {  50     public ApplicationDbContext()  51         : base("DefaultConnection", throwIfV1Schema: false) => Database.SetInitializer<ApplicationDbContext>(null);  52  53     public static ApplicationDbContext Create() => new ApplicationDbContext();  54  55  56   }

View Code

　　第二步修改注册用户的代码，注册新用户的时候需要选择所属的公司信息

 1  [HttpPost]   2     [AllowAnonymous]   3     [ValidateAntiForgeryToken]   4     public async Task<ActionResult> Register(AccountRegistrationModel viewModel)   5     {   6       var data = this._companyService.Queryable().Select(x => new ListItem() { Value = x.Id.ToString(), Text = x.Name });   7       this.ViewBag.companylist = data;   8   9       // Ensure we have a valid viewModel to work with  10       if (!this.ModelState.IsValid)  11       {  12         return this.View(viewModel);  13       }  14  15       // Try to create a user with the given identity  16       try  17       {  18         // Prepare the identity with the provided information  19         var user = new ApplicationUser  20         {  21           UserName = viewModel.Username,  22           FullName = viewModel.Lastname + "." + viewModel.Firstname,  23           CompanyCode = viewModel.CompanyCode,  24           CompanyName = viewModel.CompanyName,  25           TenantId=viewModel.TenantId,  26           Email = viewModel.Email,  27           AccountType = 0  28  29         };  30         var result = await this.UserManager.CreateAsync(user, viewModel.Password);  31  32         // If the user could not be created  33         if (!result.Succeeded)  34         {  35           // Add all errors to the page so they can be used to display what went wrong  36           this.AddErrors(result);  37  38           return this.View(viewModel);  39         }  40  41         // If the user was able to be created we can sign it in immediately  42         // Note: Consider using the email verification proces  43         await this.SignInAsync(user, true);  44  45         return this.RedirectToLocal();  46       }  47       catch (DbEntityValidationException ex)  48       {  49         // Add all errors to the page so they can be used to display what went wrong  50         this.AddErrors(ex);  51  52         return this.View(viewModel);  53       }  54     }

AccountController.cs

第三步读取登录用户的TenantId 在用户查询和新增修改时把TenantId插入到表中,这里需要引用

Z.EntityFramework.Plus，这个是免费开源的一个类库，功能强大

 1  public StoreContext()   2         : base("Name=DefaultConnection") {   3       //获取登录用户信息,tenantid   4       var claimsidentity = (ClaimsIdentity)HttpContext.Current.User.Identity;   5       var tenantclaim = claimsidentity?.FindFirst("http://schemas.microsoft.com/identity/claims/tenantid");   6       var tenantid = Convert.ToInt32(tenantclaim?.Value);   7       //设置当对Work对象进行查询时默认添加过滤条件   8       QueryFilterManager.Filter<Work>(q => q.Where(x => x.TenantId == tenantid));   9       //设置当对Order对象进行查询时默认添加过滤条件  10       QueryFilterManager.Filter<Order>(q => q.Where(x => x.TenantId == tenantid));  11     }  12  13  public override Task<int> SaveChangesAsync(CancellationToken cancellationToken)  14     {  15       var currentDateTime = DateTime.Now;  16       var claimsidentity = (ClaimsIdentity)HttpContext.Current.User.Identity;  17       var tenantclaim = claimsidentity?.FindFirst("http://schemas.microsoft.com/identity/claims/tenantid");  18       var tenantid = Convert.ToInt32(tenantclaim?.Value);  19       foreach (var auditableEntity in this.ChangeTracker.Entries<Entity>())  20       {  21         if (auditableEntity.State == EntityState.Added || auditableEntity.State == EntityState.Modified)  22         {  23           //auditableEntity.Entity.LastModifiedDate = currentDateTime;  24           switch (auditableEntity.State)  25           {  26             case EntityState.Added:  27               auditableEntity.Property("LastModifiedDate").IsModified = false;  28               auditableEntity.Property("LastModifiedBy").IsModified = false;  29               auditableEntity.Entity.CreatedDate = currentDateTime;  30               auditableEntity.Entity.CreatedBy = claimsidentity.Name;  31               auditableEntity.Entity.TenantId = tenantid;  32               break;  33             case EntityState.Modified:  34               auditableEntity.Property("CreatedDate").IsModified = false;  35               auditableEntity.Property("CreatedBy").IsModified = false;  36               auditableEntity.Entity.LastModifiedDate = currentDateTime;  37               auditableEntity.Entity.LastModifiedBy = claimsidentity.Name;  38               auditableEntity.Entity.TenantId = tenantid;  39               //if (auditableEntity.Property(p => p.Created).IsModified || auditableEntity.Property(p => p.CreatedBy).IsModified)  40               //{  41               //    throw new DbEntityValidationException(string.Format("Attempt to change created audit trails on a modified {0}", auditableEntity.Entity.GetType().FullName));  42               //}  43               break;  44           }  45         }  46       }  47       return base.SaveChangesAsync(cancellationToken);  48     }  49  50     public override int SaveChanges()  51     {  52       var currentDateTime = DateTime.Now;  53       var claimsidentity =(ClaimsIdentity)HttpContext.Current.User.Identity;  54       var tenantclaim = claimsidentity?.FindFirst("http://schemas.microsoft.com/identity/claims/tenantid");  55       var tenantid = Convert.ToInt32(tenantclaim?.Value);  56       foreach (var auditableEntity in this.ChangeTracker.Entries<Entity>())  57       {  58         if (auditableEntity.State == EntityState.Added || auditableEntity.State == EntityState.Modified)  59         {  60           auditableEntity.Entity.LastModifiedDate = currentDateTime;  61           switch (auditableEntity.State)  62           {  63             case EntityState.Added:  64               auditableEntity.Property("LastModifiedDate").IsModified = false;  65               auditableEntity.Property("LastModifiedBy").IsModified = false;  66               auditableEntity.Entity.CreatedDate = currentDateTime;  67               auditableEntity.Entity.CreatedBy = claimsidentity.Name;  68               auditableEntity.Entity.TenantId = tenantid;  69               break;  70             case EntityState.Modified:  71               auditableEntity.Property("CreatedDate").IsModified = false;  72               auditableEntity.Property("CreatedBy").IsModified = false;  73               auditableEntity.Entity.LastModifiedDate = currentDateTime;  74               auditableEntity.Entity.LastModifiedBy = claimsidentity.Name;  75               auditableEntity.Entity.TenantId = tenantid;  76               break;  77           }  78         }  79       }  80       return base.SaveChanges();  81     }

DbContext.cs

经过以上3步就实现一个简单的多租户查询数据的功能。

希望对大家有用。