Question

使用.NET Core 2.2.300和Entity Framework Core 2.2.4。

我在SQL Server数据库中得到了两个具有相似内容的表，所以我写了一个查询：

SELECT
    A.guid_id AS Id
    , A.document AS Document
FROM TableA A
WHERE
    A.guid_user_id = 'valid guid in here'
UNION ALL
SELECT
    B.guid_id AS Id
    , B.user_document AS Document
FROM TableB B
WHERE
    B.guid_user_id = 'valid guid in here'

当我运行它时它会起作用，并且会带来我需要的结果。列类型也匹配。在这个C＃项目中，我得到了一个像这样的类：

using System;

namespace MyProject.Domain.Entities
{
    public class UserDocument
    {
        public Guid? Id;
        public string Document;
    }
}

对于我的DbContext，我得到了此类：

...
public class MyDbContext : DbContext
    {
        private readonly IHostingEnvironment _env;
        public MyDbContext(IHostingEnvironment env)
        {
            _env = env;
        } 

        ... some DbSets in here that are working fine ...
        public DbQuery<UserDocument> UserDocuments { get; set; }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {

            ... a couple "modelBuilder.ApplyConfiguration(config instance);" for the DbSets ...

            base.OnModelCreating(modelBuilder);
        }
    }

在我的存储库类中：

public IEnumerable<UserDocument> GetUserDocuments(string accountId)
        {
            string query = $@"SELECT
                                  A.guid_id AS Id
                                  , A.document AS Document
                              FROM TableA A
                              WHERE
                                  A.guid_user_id = '{accountId}'
                              UNION ALL
                              SELECT
                                  B.guid_id AS Id
                                  , B.user_document AS Document
                              FROM TableB B
                              WHERE
                                  B.guid_user_id = '{accountId}';";
            #pragma warning disable EF1000 // Possible SQL injection vulnerability, I know, but it is just for testing.
            return Db.UserDocuments.FromSql(query).ToList(); // Db holds an instance of MyDbContext
            #pragma warning restore EF1000
        }

它会运行并返回原本应有的正确数量的对象，但是它们都具有空值的属性！

我想念什么吗？

我正在寻找一种获得预期结果的方法，而不必为TableA和TableB创建DbSet来创建联合。有什么办法吗？

我的DbSet一切正常，但是此DbQuery不能正常工作。

Answer 1

我只是忘了在模型中添加getter和setter。看起来像这样可以正常工作：

using System;

namespace MyProject.Domain.Entities
{
    public class UserDocument
    {
        public Guid? Id { get; set;}
        public string Document { get; set;}
    }
}

dbQuery返回空值

1 个答案: