Question

我正在尝试从一个表到另一个表访问一个值。我有一个包含PainCategoryId的表PainCategories和一个包含PainCategoryId的表Triage。我试图通过Triage运行查询，以将该Id值与PainCategory表中的值进行比较。分类表包含多个行，其PainCategoryId为1，PainCategory表中只有一个PainCategoryId = 1。如果有人能提供帮助，我们将不胜感激。

这是我控制器中的linq：

 tt.painCats = db.PainCategories.ToList().Where(p => p.CompanyId == CompanyId);

tt.triages = db.Triages.ToList().Where(t => t.PainCategoryId == tt.painCats.
Contains(t.PainCategoryId)); //Error is in this line because it is just not done
//right with the Contains.

分类模型：

public class Triage
    {
        public int Id { get; set; }
        public string Status { get; set; }
        public int PainCategoryId { get; set; }

        public virtual PainCategory PainCategory { get; set; }
    }

PainCategory模型：

public class PainCategory
    {
        public PainCategory()
        {
            Triages = new HashSet<Triage>();
        }
        public int PainCategoryId { get; set; }
        public string Title { get; set; }

        public virtual ICollection<Triage> Triages { get; set; }
    }

查看剃须刀电话：

foreach (var item in Model.painCats)
        {
            @Html.Label(item.Title)<br/>
            foreach(var tri in Model.triages)
            {
                @Html.RadioButton(tri.PainCategory.Title, tri.Order)
                @Html.Label(tri.Description)<br/>
            }
        }

Answer 1

肖恩，

你能试试吗

// This doesn't work because db.Triages is not List<T>, 
// the Contains method only applies to Lists
tt.triages = db.Triages.ToList().Where(t => tt.painCats.Contains(t.PainCategoryId));

更新

尝试使用Any运算符，如下所示：

// The Any method is a core linq method and is implemented for both Enumerable and Queryable
tt.triages = db.Triages.ToList().Where(t => tt.painCats.Any(cat => t.PainCategoryId == cat.PainCategoryId));

在ASP.net MVC中通过表访问另一个表的Linq查询

1 个答案: