Question

我使用Entity Framework Core 1.1.0和EntityFrameworkCore.SqlServer 1.1.0作为DataBase提供程序（从注释添加此信息）。和SQL Server 2014.
我有这个型号：

public class User
{
  public int Id { get; set; }
  public virtual ICollection<IdentityUserRole> Roles { get; }
}

public class IdentityUserRole
{
  public int RoleId { get; set; }
  public int UserId { get; set; }
}

我使用此代码：

IQueryable<User> query = context.Set<User>();
IQueryable<User> query2 = query.Include(u => u.Roles);

当我调用query.ToList()时，我有一个SQL查询：

SELECT [u].[Id], [u].[Email], [u].[UserName]
FROM [User] AS [u]

当我致电query2.ToList()时，我有两个SQL查询：
的 1

SELECT [u].[Id], [u].[Email], [u].[UserName]
FROM [User] AS [u]
ORDER BY [u].[Id]

2

SELECT [i].[UserId], [i].[RoleId]
FROM [IdentityUserRole<int>] AS [i]
WHERE EXISTS (
    SELECT 1
    FROM [User] AS [u]
    WHERE [i].[UserId] = [u].[Id])
ORDER BY [i].[UserId]

为什么EF在SQL查询中添加ORDER BY [u].[Id]和ORDER BY [i].[UserId]？一切正常，没有任何ORDER BY陈述我有这个问题，因为如果我调用query2.OrderByDescending(q => q.Id)我有这个无效的SQL：

SELECT [u].[Id], [u].[Email], [u].[UserName]
    FROM [User] AS [u]
    ORDER BY [u].[Id] DESC, [u].[Id]

SQL-server返回异常：

已按列表顺序多次指定列。

EF Core .Include（）ICollection属性和隐式OrderBy？

0 个答案: