C# 如何通过传入对象使用实体框架进行更新
如何使用实体框架进行更新?我正在传递带有更新值的对象,但没有看到更新方法C# 如何通过传入对象使用实体框架进行更新,c#,entity-framework,asp.net-mvc-4,C#,Entity Framework,Asp.net Mvc 4,如何使用实体框架进行更新?我正在传递带有更新值的对象,但没有看到更新方法 public void UpdateRecipient(Domain.Entities.RecipientEntity recipient) { using (EfDbContext context = CreateEfDbContext(recipient.ApplicationId.ToString())) { context.Recipients
public void UpdateRecipient(Domain.Entities.RecipientEntity recipient)
{
using (EfDbContext context = CreateEfDbContext(recipient.ApplicationId.ToString()))
{
context.Recipients. //?? I don't see an update method
context.SaveChanges();
}
}
三个步骤:
using (EfDbContext context = CreateEfDbContext(recipient.ApplicationId.ToString()))
{
var toUpdate = context.Recipients.SingleOrDefault(r => r.Id == recipient.Id);
if (toUpdate != null)
{
toUpdate.Field1 = recipient.Field1;
// Map over any other field data here.
context.SaveChanges();
}
else
{
// Handle this case however you see fit. Log an error, throw an error, etc...
}
}
三个步骤:
using (EfDbContext context = CreateEfDbContext(recipient.ApplicationId.ToString()))
{
var toUpdate = context.Recipients.SingleOrDefault(r => r.Id == recipient.Id);
if (toUpdate != null)
{
toUpdate.Field1 = recipient.Field1;
// Map over any other field data here.
context.SaveChanges();
}
else
{
// Handle this case however you see fit. Log an error, throw an error, etc...
}
}
如果要更新记录,请执行以下操作:
//Retrieve the entity to be updated
Entity row = context.Recipients.Single(a => a.Id == recipient.Id);
//Update a column
row.Name = recipient.Name;
//Save changes
context.SaveChanges();
如果要同时更新/添加内容,请执行以下操作:
if(!context.Recipients.Any(a => Id == recipient.Id))
{
context.Recipients.Add(recipient);
}
else
{
Entity row = context.Recipients.Single(a => a.Id == recipient.Id);
row.Name = recipient.Name;
}
context.SaveChanges();
如果要更新记录,请执行以下操作:
//Retrieve the entity to be updated
Entity row = context.Recipients.Single(a => a.Id == recipient.Id);
//Update a column
row.Name = recipient.Name;
//Save changes
context.SaveChanges();
如果要同时更新/添加内容,请执行以下操作:
if(!context.Recipients.Any(a => Id == recipient.Id))
{
context.Recipients.Add(recipient);
}
else
{
Entity row = context.Recipients.Single(a => a.Id == recipient.Id);
row.Name = recipient.Name;
}
context.SaveChanges();
还有一种方法可以更新对象,而无需再次从数据库中重新获取对象,从而节省了访问数据库的成本。要附加的对象的主键必须有一个值
SaveChanges()
方法还有一种方法可以更新对象,而无需再次从数据库中重新获取对象,从而节省了访问数据库的成本。要附加的对象的主键必须有一个值
SaveChanges()
方法