Question

我不得不将一对多改为多对多关系。对于前者，用户在注册时被分配了一个companyId。他们可以从数据库返回的唯一文档是在我的Web Api中使用where语句控制的。既然可以为用户分配许多公司，我需要更改where语句来做同样的事情。到目前为止，我已经创建了联结表。我在访问它并正确返回时遇到问题。

公司类

public class Company
{
    public int CompanyId { get; set; }
    public string CompanyName { get; set; }

    public int UserCompanyId { get; set; }
    public virtual UserCompany UserCompany { get; set; }
 }

UserClass的

public class ApplicationUser : IdentityUser
{
    public async Task<ClaimsIdentity>
        GenerateUserIdentityAsync(UserManager<ApplicationUser> manager)
    {
        var userIdentity = await manager
            .CreateIdentityAsync(this, DefaultAuthenticationTypes.ApplicationCookie);
        return userIdentity;
    }
    public int UserCompanyId { get; set; }
    public virtual UserCompany UserCompany { get; set; }

}

接合表

 public class UserCompany
{
    [Key]
    public int UCompanyId { get; set; }

    public string Id { get; set; }
    public int CompanyId { get; set; }
}

ApiController

 public IEnumerable<Document> GetDocuments()
    {
        var manager = new UserManager<ApplicationUser>(new UserStore<ApplicationUser>(new ApplicationDbContext()));
        var user = manager.FindById(User.Identity.GetUserId());
        using (var context = new ApplicationDbContext())
        {
            return context.UserCompanies
                .Where(j => j.CompanyId == user.UserCompany.CompanyId)
                .ToList();
        }
    }

错误发生在.ToList（）

错误1无法将类型'System.Collections.Generic.List'隐式转换为'System.Collections.Generic.IEnumerable'。存在显式转换（您是否错过了演员？）

更新

 // GET api/<controller>
      public List<Document> GetDocuments()
    {
        var manager = new UserManager<ApplicationUser>(new UserStore<ApplicationUser>(new ApplicationDbContext()));
        var user = manager.FindById(User.Identity.GetUserId());
        using (var context = new ApplicationDbContext())
        {
            return context.Documents
                .Where(j => j.CompanyId == user.UserCompany.UCompanyId)
                .ToList();
        }
    }

文件类

 public class Document
{
    public int DocumentId { get; set; }
    public DateTime DocumentDate { get; set; }
    public string DocumentUrl { get; set; }
    public DateTime DocumentUploadDate { get; set; }
    public string DocumentUploadedBy { get; set; }

    public int CompanyId { get; set; }
    public virtual Company Company { get; set; }
 }

我将IEnumberable更改为List。我仍然没有做对，我的ApiController错误

非静态方法需要目标。

我也发布了我的文档类。我迷失了如何使这项工作。第一次与多对多关系

这是stacktrace

at System.Reflection.RuntimeMethodInfo.CheckConsistency（Object target）在System.Reflection.RuntimeMethodInfo.InvokeArgumentsCheck（Object obj，BindingFlags invokeAttr，Binder binder，Object []参数，CultureInfo文化）在System.Reflection.RuntimeMethodInfo.Invoke（Object obj，BindingFlags invokeAttr，Binder binder，Object []参数，CultureInfo文化）在System.Reflection.RuntimePropertyInfo.GetValue（Object obj，BindingFlags invokeAttr，Binder binder，Object [] index，CultureInfo culture）在System.Reflection.RuntimePropertyInfo.GetValue（Object obj，Object [] index）在System.Data.Entity.Core.Objects.ELinq.QueryParameterExpression.TryGetFieldOrPropertyValue（MemberExpression me，Object instance，Object＆amp; memberValue）在System.Data.Entity.Core.Objects.ELinq.QueryParameterExpression.TryEvaluatePath（表达式表达式，ConstantExpression＆amp; constantExpression） at System.Data.Entity.Core.Objects.ELinq.QueryParameterExpression.EvaluateParameter（Object [] arguments）在System.Data.Entity.Core.Objects.ELinq.ELinqQueryState.GetExecutionPlan（Nullable 1 forMergeOption) at System.Data.Entity.Core.Objects.ObjectQuery 1.＆lt;＆gt; c__DisplayClass7.b__6（）在System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction [T]（Func 1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess) at System.Data.Entity.Core.Objects.ObjectQuery 1.＆lt;＆gt; c__DisplayClass7.b__5（） at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute [TResult]（Func 1 operation) at System.Data.Entity.Core.Objects.ObjectQuery 1.GetResults（Nullable 1 forMergeOption) at System.Data.Entity.Core.Objects.ObjectQuery 1..GetEnumerator＆gt; b__0（）在System.Data.Entity.Internal.LazyEnumerator 1.MoveNext() at System.Collections.Generic.List 1..ctor（IEnumerable 1 collection) at System.Linq.Enumerable.ToList[TSource](IEnumerable 1来源）在C：\ Development \ TransparentEnergy \ TransparentEnergy \ ControllersAPI \ apiDocumentUserController.cs中的TransparentEnergy.ControllersAPI.apiDocumentUserController.GetDocuments（）：第29行在lambda_method（Closure，Object，Object []）在System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor。＆lt;＆gt; c__DisplayClass10.b__9（Object instance，Object [] methodParameters）在System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.Execute（Object instance，Object [] arguments）在System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ExecuteAsync（HttpControllerContext controllerContext，IDictionary`2 arguments，CancellationToken cancellationToken）

Answer 1

我认为这是因为您返回了一个List，并且您的函数返回的类型是IEnumerable，请尝试：

public List<Document> GetDocuments()
    {
        var manager = new UserManager<ApplicationUser>(new UserStore<ApplicationUser>(new ApplicationDbContext()));
        var user = manager.FindById(User.Identity.GetUserId());
        using (var context = new ApplicationDbContext())
        {
            return context.UserCompanies
                .Where(j => j.CompanyId == user.UserCompany.CompanyId)
                .ToList();
        }
    }

如何建立多对多的关系

1 个答案: