C＃中的LINQ to SQL连接字符串（新手） [英] C# Linq to SQL connection string (newbie)

问题描述

我是一个新的LINQ to SQL的学习，这是我的第一个创建一个数据浏览器程序的尝试。这个想法很简单，我想创建一个软件，它能够在数据库中查看表的内容。这就是它。

i am a new linq to sql learner and this is my very first attempt to create a data viewer program. The idea is simple, i'd like to create a software that is able to view content of a table in a database. That's it.

我有一个早期的问题已经在这里，我已经看过很多tutes和网上的文章，但我仍然无法修复的bug。

I got an early problem here already and i have seen many tutes and articles online but I still cant fix the bug.

下面是我的代码：

    static void Main(string[] args)
    {
        string cs = "Data Source=localhost;Initial Catalog=somedb;Integrated Security=SSPI;";

        var db = new DataClasses1DataContext(cs);
        db.Connection.Open();

        foreach (var b in db.Mapping.GetTables())
            Console.WriteLine(b.TableName);

        Console.ReadKey(true);
    }

当我试图检查 db.connection.equals （NULL）; 返回假，所以我想我已经成功地连接到数据库，因为没有错误可言。但上面的代码不会打印出任何内容到屏幕上。

When I tried to check db.connection.equals(null); it returns false, so i thought i have connected successfully to the database since there is no error at all. But the code above doesn't print anything out to the screen.

我有点迷路了，不知道是怎么回事。 ？有谁知道是怎么回事错在这里。

I kind of lost and don't know what's going on here. Does anyone know what is going wrong here?

推荐答案

好吧，让我们来看看其中的一些行：

Ok, let's look at some of these lines:

var db = new DataClasses1DataContext(cs);

这是一个构造一个完全正常的和精细的呼叫。由于DataContext的实现IDisposable，当你使用它的实际，考虑使用using语句。

This is a perfectly normal and fine call to a constructor. Since DataContext implements IDisposable, when you are using it for real, consider using the using statement.

using (var db = new DataClasses1DataContext(cs))
{
  // do stuff with db here
} // when leaving the block, db is disposed - even in the case of an exception.

---

---

db.Connection.Open();

不要这样做。 DataContext的打开和关闭连接时，它需要。

Don't do this. DataContext will open and close the connection when it needs to.

foreach (var b in db.Mapping.GetTables())
  Console.WriteLine(b.TableName); 

嗯，也许是在映射没有桌子。你是从服务器资源管理器拖放表到设计表面？

Hmm, maybe there are no tables in the mapping. Did you drag a table onto the designer surface from the server explorer?

大多数人会质疑，而不是细读的映射表。考虑下面的代码，而不是：

Most people would query a table instead of perusing the mappings. Consider this code instead:

foreach (var customer in db.Customer.Take(10))
{
  Console.WriteLine(customer.Name); 
}

---

下面是展示如何视频

---

Here's a video showing how to drag a table onto the designer surface from the server explorer:

的 http://www.youtube.com/watch?v=z9L11qrw9gk

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