在遍历 EF Core 5 中的多个条件包含后查询任何条目

Question

考虑以下数据模型：

• 一个委托人有多个角色（多对多）；
• 角色授予多个权限（多对多）；

现在我想使用 LINQ 来确定 Principal 是否具有权限，即他是否在任何拥有此权限的角色中。 对于这种情况，通常我会在连接表上使用AnyAsync，但由于我要遍历多个连接表，所以我真的很挣扎。我最初想出了这个：

    var query = context.Principals
        .Where(p => p.Id == "SomeUUID")
        .Include(p => p.Roles)
        .ThenInclude(r => r.Permissions
        .Where(p => p.Name == "SomePermission"));

但现在我必须再次通过 Principal 遍历（可能在内存中）附加的角色以搜索 Any 权限。

有没有办法可以在同一个查询中顺利应用此检查？

编辑：这是生成的 SQL 以补充 Parks 的（底部）答案：

SELECT CASE
      WHEN EXISTS (
          SELECT 1
          FROM [Principals] AS [a]
          INNER JOIN (
              SELECT [a1].[Id], [a1].[Description], [a1].[DisplayName], [a0].[RoleId], [a0].[PrincipalId]
              FROM [PrincipalRoles] AS [a0]
              INNER JOIN [Roles] AS [a1] ON [a0].[RoleId] = [a1].[Id]
          ) AS [t] ON [a].[PrincipalId] = [t].[PrincipalId]
          INNER JOIN (
              SELECT [a3].[Id], [a3].[Name], [a2].[RoleId], [a2].[PermissionId]
              FROM [RolePermissions] AS [a2]
              INNER JOIN [Permissions] AS [a3] ON [a2].[PermissionId] = [a3].[Id]
          ) AS [t0] ON [t].[Id] = [t0].[RoleId]
          WHERE ([a].[PrincipalId] = "SomePrincipal") AND ([t0].[Name] = "SomePermission")) THEN CAST(1 AS bit)
      ELSE CAST(0 AS bit)
END

SELECT CASE
      WHEN EXISTS (
          SELECT 1
          FROM [Principals] AS [a]
          WHERE ([a].[PrincipalId] = "SomePrincipal") AND EXISTS (
              SELECT 1
              FROM [PrincipalRoles] AS [a0]
              INNER JOIN [Roles] AS [a1] ON [a0].[RoleId] = [a1].[Id]
              WHERE ([a].[PrincipalId] = [a0].[PrincipalId]) AND EXISTS (
                  SELECT 1
                  FROM [RolePermissions] AS [a2]
                  INNER JOIN [Permissions] AS [a3] ON [a2].[PermissionId] = [a3].[Id]
                  WHERE ([a1].[Id] = [a2].[RoleId]) AND ([a3].[Name] = "SomePermission")))) THEN CAST(1 AS bit)
      ELSE CAST(0 AS bit)
END

Answer 1

要查看主体是否在 Roles 中具有在 Permissions 中具有 Permission 的 Role，您可以使用以下 Where 条件：

var result = await context.Principals
    .Where(p => p.Id == "SomeUUID" && p.Roles.Any(r => r.Permissions.Any(x => x.Name == "SomePermission")))
    .FirstOrDefaultAsync();

如果 result 为 null，则 Principal 不存在或没有您检查的权限。如果result 仍然需要导航属性，那么您可以添加最初包含在您的问题中的包含语句。

Answer 2

您可能正在寻找此查询：

var hasPermssion = context.Principals
    .Where(p => p.Id == "SomeUUID")
    .SelectMany(p => p.Roles)
    .SelectMany(r => r.Permissions)
    .Any(p => p.Name == "SomePermission");

生成的SQL语句如下：

SELECT CASE
      WHEN EXISTS (
          SELECT 1
          FROM [Principals] AS [a]
          INNER JOIN (
              SELECT [a1].[Id], [a1].[Description], [a1].[DisplayName], [a0].[RoleId], [a0].[PrincipalId]
              FROM [PrincipalRoles] AS [a0]
              INNER JOIN [Roles] AS [a1] ON [a0].[RoleId] = [a1].[Id]
          ) AS [t] ON [a].[PrincipalId] = [t].[PrincipalId]
          INNER JOIN (
              SELECT [a3].[Id], [a3].[Name], [a2].[RoleId], [a2].[PermissionId]
              FROM [RolePermissions] AS [a2]
              INNER JOIN [Permissions] AS [a3] ON [a2].[PermissionId] = [a3].[Id]
          ) AS [t0] ON [t].[Id] = [t0].[RoleId]
          WHERE ([a].[PrincipalId] = "SomePrincipal") AND ([t0].[Name] = "SomePermission")) THEN CAST(1 AS bit)
      ELSE CAST(0 AS bit)
END