C# 使用实体框架模型插入数据
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Insert data using Entity Framework model
提问by Rocshy
I'm trying to insert some data in my database using Entity Framework model, but for some unknown reasons to me, it does nothing.
我正在尝试使用实体框架模型在我的数据库中插入一些数据，但由于某些未知的原因，它什么也没做。
Am I missing something here?
我在这里错过了什么吗？
using (var context = new DatabaseEntities())
{
var t = new test
{
ID = Guid.NewGuid(),
name = "blah",
};
context.AddTotest(t);
context.SaveChanges();
}
采纳答案by Developer
It should be:
它应该是：
context.TableName.AddObject(TableEntityInstance);
Where:
在哪里：
TableName: the name of the table in the database.TableEntityInstance: an instance of the table entity class.
TableName: 数据库中表的名称。TableEntityInstance：表实体类的一个实例。
If your table is Orders, then:
如果您的表是Orders，则：
Order order = new Order();
context.Orders.AddObject(order);
For example:
例如：
var id = Guid.NewGuid();
// insert
using (var db = new EfContext("name=EfSample"))
{
var customers = db.Set<Customer>();
customers.Add( new Customer { CustomerId = id, Name = "John Doe" } );
db.SaveChanges();
}
Here is a live example:
这是一个活生生的例子：
public void UpdatePlayerScreen(byte[] imageBytes, string installationKey)
{
var player = (from p in this.ObjectContext.Players where p.InstallationKey == installationKey select p).FirstOrDefault();
var current = (from d in this.ObjectContext.Screenshots where d.PlayerID == player.ID select d).FirstOrDefault();
if (current != null)
{
current.Screen = imageBytes;
current.Refreshed = DateTime.Now;
this.ObjectContext.SaveChanges();
}
else
{
Screenshot screenshot = new Screenshot();
screenshot.ID = Guid.NewGuid();
screenshot.Interval = 1000;
screenshot.IsTurnedOn = true;
screenshot.PlayerID = player.ID;
screenshot.Refreshed = DateTime.Now;
screenshot.Screen = imageBytes;
this.ObjectContext.Screenshots.AddObject(screenshot);
this.ObjectContext.SaveChanges();
}
}
回答by Nawed Nabi Zada
var context = new DatabaseEntities();
var t = new test //Make sure you have a table called test in DB
{
ID = Guid.NewGuid(),
name = "blah",
};
context.test.Add(t);
context.SaveChanges();
Should do it
应该做
回答by sanket parikh
[HttpPost] // it use when you write logic on button click event
[HttpPost] // 在按钮点击事件上编写逻辑时使用
public ActionResult DemoInsert(EmployeeModel emp)
{
Employee emptbl = new Employee(); // make object of table
emptbl.EmpName = emp.EmpName;
emptbl.EmpAddress = emp.EmpAddress; // add if any field you want insert
dbc.Employees.Add(emptbl); // pass the table object
dbc.SaveChanges();
return View();
}
回答by yu yang Jian
I'm using EF6, and I find something strange,
我正在使用 EF6，但我发现了一些奇怪的东西，
Suppose Customer has constructor with parameter ,
假设 Customer 有带参数的构造函数，
if I use new Customer(id, "name"), and do
如果我使用 new Customer(id, "name"), 并且做
using (var db = new EfContext("name=EfSample"))
{
db.Customers.Add( new Customer(id, "name") );
db.SaveChanges();
}
It run through without error, but when I look into the DataBase, I find in fact that the data Is NOT be Inserted,
它运行没有错误，但是当我查看数据库时，我发现实际上没有插入数据，
But if I add the curly brackets, use new Customer(id, "name"){}and do
但是如果我添加大括号，请使用new Customer(id, "name"){}并执行
using (var db = new EfContext("name=EfSample"))
{
db.Customers.Add( new Customer(id, "name"){} );
db.SaveChanges();
}
the data will then actually BE Inserted,
然后数据将被实际插入，
seems the Curly Brackets make the difference, I guess that only when add Curly Brackets, entity framework will recognize this is a real concrete data.
看起来Curly Brackets 有所作为，我猜只有当添加Curly Brackets 时，实体框架才会识别这是一个真正的具体数据。
