使用addtotable C＃保存到数据库实体 [英] Save to database entities using addtotable C#

问题描述

 private CoffeeShopDatabaseEntities1 cse = new CoffeeShopDatabaseEntities1（）; 
 
 TblProduct product = new TblProduct（）; 
 product.Descrption = descrptiontxt.Text; 
 product.Price = decimal.Parse（pricetxt.Text）; 
 product.Image = bytedata; 
 product.ProductType =（int）cbocatgrey.SelectedValue; 

现在我要保存这个  ; 产品 使用此代码将实体
添加到数据库中：

 cse.AddtoTBlProduct（product）; 

但是  addtoTBlproduct  
不会在Visual Studio 2017中插入。

它在Visual Studio 2010中工作。请帮助我。

注意：

实体 objectcontext但数据库自我dbcotext我不知道如何在MS VS 2017中将其添加为数据库上下文 

我可以在MS VS 2010中添加基于服务的数据库 

解决方案

正在进行DBcontext用于CRUD操作。

使用System; 
使用System.Collections.Generic; 
使用System.Linq; 
使用System .Data.Entity; 
使用实体; 
使用DAL.Model; 
 
名称空间DAL.DAO 
 {
公共类DAOStudent：IDAOStudent 
 {
 public DTOStudent GetStudentById（Int32 id）
 {
 var dto = new DTOStudent（）; 
 using（var context = new CUDataEntities（））
 {
 var student =（context.Students.Where（a => a.StudentID == id））。SingleOrDefault（）; 
 
 if（student！= null）
 { 
 dto.StudentID = student.StudentID; 
 dto.FirstName = student.FirstName; 
 dto.LastName = student。姓; 
 dto.EnrollmentDate = student.EnrollmentDate; 
 
 var enrolllments = new DAOEnrollment（）。GetEntrollmentsByStudentId（id）.ToList（）; 
 var courses = new DAOCourse（）。GetCoursesByStudentCourseId（student.StudentID）。ToList（）; 
 
 dto.EnrollsandCourses =（来自参与计划
加入b，a.CourseID等于b.CourseID 
的课程选择新的DTOEnrollandCourse（）
 {Title = b .Title，Credits = b.Credits，Grade = a.Grade}）。ToList（）; 
} 
} 
 
返回dto; 
} 
 public void CreateStudent（DTOStudent dto）
 {
 using（var context = new CUDataEntities（））
 {
 var student = new Student 
 {
 FirstName = dto.FirstName，
 LastName = dto.LastName，
 EnrollmentDate = dto.EnrollmentDate 
}; 
 
 context.Students.Add（学生）; 
 context.SaveChanges（）; 
} 
} 
 
 public void DeleteStudent（int id）
 {
学生; 
 using（var context = new CUDataEntities（））
 {
 student =（context.Students.Where（a => a.StudentID == id））。SingleOrDefault（）; 
} 
 
使用（var newContext = new CUDataEntities（））
 {
 newContext.Entry（student）.State = System.Data.Entity.EntityState.Deleted ; 
 newContext.SaveChanges（）; 
} 
} 
 
公开列表< DTOStudent> GetStudents（）
 {
 var dtos = new List< DTOStudent>（）; 
 
 using（var context = new CUDataEntities（））
 {
 var students = context.Students.ToList（）; 
 
 foreach（学生中的var）
 {
 var dto = new DTOStudent 
 {
 StudentID = stud.StudentID，
 FirstName = stud.FirstName，
 LastName = stud.LastName，
 EnrollmentDate = stud.EnrollmentDate 
}; 
 
 dtos.Add（dto）; 
} 
} 
 
返回dtos; 
} 
 
 public void UpdateStudent（DTOStudent dto）
 {
 var student = new Student（）; 
 
使用（var context = new CUDataEntities（））
 {
 student =（context.Students.Where（a => a.StudentID == dto.StudentID）） .SingleOrDefault（）; 
} 
 
 if（student！= null）
 {
 student.FirstName = dto.FirstName; 
 student.LastName = dto.LastName; 
 student.EnrollmentDate = dto.EnrollmentDate; 
} 
 
使用（var dbcontext = new CUDataEntities（））
 {
 if（student！= null）
 {
 dbcontext。 Entry（student）.State = EntityState.Modified; 
 dbcontext.SaveChanges（）; 
} 
} 
} 
} 
} 
 

private CoffeeShopDatabaseEntities1 cse = new CoffeeShopDatabaseEntities1();

TblProduct product = new TblProduct();
product.Descrption = descrptiontxt.Text;
product.Price = decimal.Parse(pricetxt.Text);
product.Image = bytedata;
product.ProductType = (int)cbocatgrey.SelectedValue;

Now I want to save this product entity to the database using this code:

cse.AddtoTBlProduct(product);

but addtoTBlproduct does not insert in Visual Studio 2017.

It's working in Visual Studio 2010. Please help me.

NOTE:

entities objectcontext but the the database it self dbcotext I don't know how to add it as database context in MS VS 2017 

I can add by service based database in MS VS 2010 

解决方案

DBcontext is being used in CRUD operations.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Data.Entity;
using Entities;
using DAL.Model;

namespace DAL.DAO
{
    public class DAOStudent : IDAOStudent
    {
        public DTOStudent GetStudentById(Int32 id)
        {
            var dto = new DTOStudent();
            using (var context = new CUDataEntities())
            {
                var student = (context.Students.Where(a => a.StudentID == id)).SingleOrDefault();

                if (student != null)
                {
                    dto.StudentID = student.StudentID;
                    dto.FirstName = student.FirstName;
                    dto.LastName = student.LastName;
                    dto.EnrollmentDate = student.EnrollmentDate;

                    var enrolllments =  new DAOEnrollment().GetEntrollmentsByStudentId(id).ToList();
                    var courses = new DAOCourse().GetCoursesByStudentCourseId(student.StudentID).ToList();

                    dto.EnrollsandCourses = (from a in enrolllments
                                  join b in courses on a.CourseID equals b.CourseID
                    select new  DTOEnrollandCourse()
                     { Title = b.Title, Credits = b.Credits, Grade = a.Grade }).ToList();
                }
            }

            return dto;
        }
        public void CreateStudent(DTOStudent dto)
        {
            using (var context = new CUDataEntities())
            {
                var student = new Student
                {
                    FirstName = dto.FirstName,
                    LastName = dto.LastName,
                    EnrollmentDate = dto.EnrollmentDate
                };

                context.Students.Add(student);
                context.SaveChanges();
            }
        }

        public void DeleteStudent(int id)
        {
            Student student;
            using (var context = new CUDataEntities())
            {
                student = (context.Students.Where(a => a.StudentID == id)).SingleOrDefault();
            }

            using (var newContext = new CUDataEntities())
            {
                newContext.Entry(student).State = System.Data.Entity.EntityState.Deleted;
                newContext.SaveChanges();
            }
        }

        public List<DTOStudent> GetStudents()
        {
            var dtos = new List<DTOStudent>();

            using (var context = new CUDataEntities())
            {
                var students = context.Students.ToList();

                foreach(var stud in students)
                {
                    var dto = new DTOStudent
                    {
                        StudentID = stud.StudentID,
                        FirstName = stud.FirstName,
                        LastName = stud.LastName,
                        EnrollmentDate = stud.EnrollmentDate
                    };

                    dtos.Add(dto);
                }
            }

            return dtos;
        }

        public void UpdateStudent(DTOStudent dto)
        {
            var student = new Student();

            using (var context = new CUDataEntities())
            {
                student = (context.Students.Where(a => a.StudentID == dto.StudentID)).SingleOrDefault();
            }

            if (student != null)
            {
                student.FirstName = dto.FirstName;
                student.LastName = dto.LastName;
                student.EnrollmentDate = dto.EnrollmentDate;
            } 

            using (var dbcontext = new CUDataEntities())
            {
                if (student != null)
                {
                    dbcontext.Entry(student).State = EntityState.Modified;
                    dbcontext.SaveChanges();
                }
            }
        }
    }
}

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