我正在尝试执行以下查询
var resultStu1 = await (from st in _context.tbl_Student
join de in _contextCNS.View_SrmCounselling_GetDegrees on st.DegreeId equals de.ID
join ex in _context.tbl_Student_Exam_Mapping_Table on st.ApplicantId equals ex.ApplicantId
where st.ApplicantId == AppId
select new
{
ApplicantId = st.ApplicantId,
Image = st.Photo,
FullName = st.FirstName.Trim() + " " + st.LastName.Trim(),
Signature = st.Signature,
Rank = ex.Rank,
Category = st.Category,
ContactNumber = st.Mobile.Substring(0, 1) + "*****" + st.Mobile.Substring(st.Mobile.Length - 1, 1),
Email = String.Format(st.Email.ToString().Substring(0, 1) + "********" + (st.Email).ToString().Substring(st.Email.Length - 4, 4)),
de.DegreeName.Trim()
}).ToListAsync();
在Controller构造函数中
public CommonController(EntityModelContext context, EntityModelContextCNS contextCNS)
{
_context = context;
_contextCNS = contextCNS;
}
我添加了两个DB Context
public class EntityModelContext : DbContext
{
public EntityModelContext(DbContextOptions<EntityModelContext> options) : base(options)
{
}
public EntityModelContext() { }
public DbSet<Student> tbl_Student { get; set; }
public DbSet<StudentExamMapping> tbl_Student_Exam_Mapping_Table { get; set; }
}
}
public class EntityModelContextCNS : DbContext
{
public EntityModelContextCNS(DbContextOptions<EntityModelContextCNS> options) : base(options)
{
}
public EntityModelContextCNS() { }
public DbSet<DegreeCNS> View_SrmCounselling_GetDegrees { get; set; }
}
这是我在Startup.cs中的ConfigureServices方法
public void ConfigureServices(IServiceCollection services)
{
// Add framework services.
services.AddMvc();
services.AddCors(options => options.AddPolicy("AllowCors",
builder =>
{
builder
.AllowAnyOrigin()
.WithMethods("GET", "PUT", "POST", "DELETE")
.AllowAnyHeader();
})
);
services.AddEntityFramework()
.AddDbContext<EntityModelContext>(options => options.UseSqlServer(Configuration["ConnectionStrings:DefaultConnection"]))
//services.AddEntityFramework()
.AddDbContext<EntityModelContextCNS>(
options => options.UseSqlServer(Configuration["ConnectionStrings:DefaultConnectionCNS"]));
//Inject an implementation of ISwaggerProvider with defaulted settings applied
services.AddSwaggerGen();
services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
}
模特：
public class Student
{
public int Id { get; set; }
public int ApplicantId { get; set; }
public string Title { get; set; }
public string Category { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public string MiddleName { get; set; }
public string Gender { get; set; }
public string Email { get; set; }
public string Mobile { get; set; }
public string Address { get; set; }
public string Photo { get; set; }
public string Signature { get; set; }
public string Biometric { get; set; }
public Nullable<System.DateTime> CreatedOn { get; set; }
public Nullable<System.DateTime> UpdatedOn { get; set; }
public string PermanentAddressState { get; set; }
public string TwelfthBoard { get; set; }
public Nullable<int> FacultyId { get; set; }
public Nullable<int> LevelId { get; set; }
public Nullable<int> DegreeId { get; set; }
public string UG_University { get; set; }
public string TenthBoard { get; set; }
public Nullable<int> SlotId { get; set; }
}
public class DegreeCNS
{
[Key]
public int ID { get; set; }
public string DegreeName { get; set; } = "";
public string Code { get; set; }
}
public class StudentExamMapping
{
public int Id { get; set; }
public Nullable<int> ApplicantId { get; set; }
public Nullable<int> ExamId { get; set; }
public Nullable<System.DateTime> ExamDate { get; set; }
public Nullable<decimal> Section1Marks { get; set; }
public Nullable<decimal> Section2Marks { get; set; }
public Nullable<decimal> Section3Marks { get; set; }
public Nullable<int> Rank { get; set; }
public Nullable<int> ScholarshipId { get; set; }
}
On执行resultStu1查询我得到ERRROR -------
System.ArgumentNullException：值不能为null。 参数名称：entityType 在Microsoft.EntityFrameworkCore.Utilities.Check.NotNull [T]（T值，String parameterName） 在Microsoft.EntityFrameworkCore.SqlServerMetadataExtensions.SqlServer（IEntityType entityType）
请帮助!!!!