MVC join 查询

   //数据库
use oa
go
create table UserInfos
(
id int identity Primary key,
username varchar(64),
Number varchar(64),
userclass varchar(64),
state varchar(64),
userparent int
)
create table Users
(
id int identity Primary key,
fathername varchar(64),
Number varchar(64),
)
 UserInfos 的userparent 和Users 的 id 相关
  public ActionResult Index()
        {
            //join查询方式一
            oaEntities1 oa = new oaEntities1();
            List<UserJoininfo> info = oa.Database.SqlQuery<UserJoininfo>("select UserInfos.id,UserInfos.username,Users.fathername from UserInfos join Users on UserInfos.userparent=Users.id").ToList();
            
            //join查询方式二linq
            var joininfo = from u in oa.UserInfos
                           join p in oa.Users on u.userparent equals p.id
                           select new
                           {
                               u.id,
                               u.username,
                               p.fathername
                           };
            //join查询方式三lamdba                        
            var Joininfod = oa.UserInfos.Join(oa.Users, a => a.userparent, b => b.id, (a, b) => new
            {
                a.id,
                a.username,
                b.fathername
            }).ToList();
          
            return View();
        }