如何在默认情况下使用Entity Framework进行C#加入DataBase - 首先,因为我正在数据库中执行此查询
public List <clsModel> list ()
{
strQuery = "select mode.modModel, bra.braIdBrand from tblModel mode join tblBrand bra on bra.braIdBrand = mode.braIdBrand";
List <clsModel> lstModel = db.Database.SqlQuery <clsModel> (strQuery) .ToList ();
return lstModel;
}
但它总是给出这个错误
附加信息:数据读取器与指定的“CadastroAtivo.Models.clsModelo”不兼容。类型为“modIdModelo”的成员在数据读取器中没有具有相同名称的相应列。
我想将模板放在一起各自的标签,但只有模板和标记是空白的(空),我不知道为什么。
班级型号:
public class clsModel
{
[Key]
public int modIdModel {get; set; }
[Required (ErrorMessage = "Enter Template Name")]
[StringLength (40, ErrorMessage = "BigName!")]
[MinLength (3, ErrorMessage = "Enter a name with at least 3 digits")]
[Display (Name = "Model")]
public string modModel {get; set; }
[Display (Name = "Mark")]
[Required (ErrorMessage = "Select brand")]
public int braIdBrand {get; set; }
[ForeignKey ("braIdBrand")]
public clsBrand Brand {get; set; }
}
品牌:
public class clsBrand
{
[Key]
public int braIdBrand {get; set; }
[Required (ErrorMessage = "Report a brand"]]
[Display (Name = "Brand")]
[StringLength (50, ErrorMessage = "BigName!")]
[MinLength (3, ErrorMessage = "Tag name is short")]
public string braBrand {get; set; }
public virtual ICollection <clsModel> Model {get; set; }
}
有谁能够帮我?
在dbcontext上做出疯狂的假设,但你可以试试这个:
var results = from model in db.clsModels
join brand in db.clsBrands on model.brand equals brand into g
select new { Model = model, Brands = g };
(目前无法在没有我的工作站或dbcontext的情况下对此进行测试,但希望您能得到这个想法)
使用Linq
的优点是它是强类型的。您可以在编译期间轻松找到错误。
你试过这个:
public List<clsModel> list()
{
strQuery = "select mode.modModel, bra.braIdBrand from tblModel mode join tblBrand bra on bra.braIdBrand = mode.braIdBrand";
IEnumerable<clsModel> result = db.ExecuteQuery<clsModel> (strQuery);
return result.ToList();
}