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Linq To Entity 的增删改查(技术储备,怕忘了)

發布時間:2025/3/20 48 豆豆
生活随笔 收集整理的這篇文章主要介紹了 Linq To Entity 的增删改查(技术储备,怕忘了) 小編覺得挺不錯的,現在分享給大家,幫大家做個參考.

1.新增Customers記錄
??????????? 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記錄
??????????? 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.刪除Customers記錄
??????????? 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.查詢Customers,返回所有記錄
??????????? using (NorthwindEntities myDb = new NorthwindEntities())
??????????? {
??????????????? dataGridView1.DataSource = myDb.Customers;
??????????? }

轉載于:https://www.cnblogs.com/mbailing/archive/2010/10/09/1846302.html

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