LinQ To Entity的增删改查(转)

本示例程序采用Northwind 示例数据库，下面开始编写代码对Customers表进行增、删、改、查等等操作。

 

1.新增Customers记录

            using (NorthwindEntities myDb = new NorthwindEntities())

            {

                Customers customer = new Customers();

 

                Random rm = new Random();

 

                customer.CustomerID = "A" + rm.Next(9999).ToString();

                customer.CompanyName = "EntLib.com Forum";

                customer.Address = "http://www.entlib.com/";

 

                myDb.AddToCustomers(customer);

 

                int count = myDb.SaveChanges();

 

                txtCustomerID.Text = customer.CustomerID;

            }

 

2.更新Customers记录

            using (NorthwindEntities myDb = new NorthwindEntities())

            {

                var query = from customer in myDb.Customers

                            where customer.CustomerID == txtCustomerID.Text.Trim()

                            select customer;

 

                foreach (var row in query)

                {

                    row.CompanyName = "Updated Company Name";

                }

 

                myDb.SaveChanges();

            }

 

3.删除Customers记录

            using (NorthwindEntities myDb = new NorthwindEntities())

            {

                var query = from customer in myDb.Customers

                            where customer.CustomerID == txtCustomerID.Text.Trim()

                            select customer;

 

                foreach (var row in query)

                {

                    myDb.DeleteObject(row);

                }

 

                myDb.SaveChanges();

            }

 

4.查询Customers，返回所有记录

            using (NorthwindEntities myDb = new NorthwindEntities())

            {

                dataGridView1.DataSource = myDb.Customers;

            }

 

本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/baobao267/archive/2010/05/27/5627763.aspx