實體框架更新

Question

我在我的項目中使用實體框架5，我想更新記錄。我該怎麼做呢？

這是我的基類。

using System; 

namespace EF_Sample09.DomainClasses 
{ 
    public abstract class BaseEntity 
    { 
     public int Id { get; set; } 

     public DateTime CreatedOn { set; get; } 
     public string CreatedBy { set; get; } 

     public DateTime ModifiedOn { set; get; } 
     public string ModifiedBy { set; get; } 
    } 
} 

Answer 1

從大ADO.NET Entity Framework Overview考慮：

using(AdventureWorksDB aw = new 
AdventureWorksDB(Settings.Default.AdventureWorks)) { 
    // find all people hired at least 5 years ago 
    Query<SalesPerson> oldSalesPeople = aw.GetQuery<SalesPerson>(
     "SELECT VALUE sp " + 
     "FROM AdventureWorks.AdventureWorksDB.SalesPeople AS sp " + 
     "WHERE sp.HireDate < @date", 
     new QueryParameter("@date", DateTime.Today.AddYears(-5))); 

    foreach(SalesPerson p in oldSalesPeople) { 
     // call the HR system through a webservice to see if this 
     // sales person has a promotion coming (note that this 
     // entity type is XML-serializable) 
     if(HRWebService.ReadyForPromotion(p)) { 
      p.Bonus += 10; // give a raise of 10% in the bonus 
      p.Title = "Senior Sales Representative"; // give a promotion 
     } 
    } 

    // push changes back to the database 
    aw.SaveChanges(); 
} 

基本上，你只需要：

• 創建ObjectContext（或DbContext）
• 取一些記錄
• 修改對象
• 呼叫的關聯的.SaveChanges()方法將這些更改寫入到數據庫

這就是它！