带有连接字符串的实体框架 DbContext 构造函数

有人可以帮助我理解以下两种将连接字符串传递给的方法DbContext?

方法#1：

public EWebDBContextEMS() : base("mainConnectionString")
{
}

和方法#2：

public EWebDBContextEMS() : base("name=mainConnectionString")
{
}

这篇文章指出 that name=...将由设计师创建，但我用纯测试DbContext代码，它也有效。

这是有意为之的行为吗？DbContext构造函数？并且在文档，它没有提到name=对于连接字符串来说是可以接受的。

非常感谢

类DBContext类注释有完整的解释。
简而言之：

• 您的第一个示例可能会创建一个名为“mainConnectionString”的数据库。
• name=xxxx 在 app.config 中按名称查找连接字符串

某些工具确实会为您将条目放入 App.config 中。
您链接的在线文档准确说明了帮助的位置。

在线帮助说：

使用给定字符串作为名称构造一个新的上下文实例 或将连接到的数据库的连接字符串 制成。请参阅课堂备注，了解如何使用它来创建 联系。

如果你去看课堂笔记，你会找到完整的解释......

///               The connection to the database (including the name of the database) can be specified in several ways.
///             If the parameterless DbContext constructor is called from a derived context, then the name of the derived context
///             is used to find a connection string in the app.config or web.config file.  If no connection string is found, then
///             the name is passed to the DefaultConnectionFactory registered on the <see cref="T:System.Data.Entity.Database"/> class.  The connection
///             factory then uses the context name as the database name in a default connection string.  (This default connection
///             string points to .\SQLEXPRESS on the local machine unless a different DefaultConnectionFactory is registered.)
///             Instead of using the derived context name, the connection/database name can also be specified explicitly by
///             passing the name to one of the DbContext constructors that takes a string.  The name can also be passed in
///             the form "name=myname", in which case the name must be found in the config file or an exception will be thrown.
///             Note that the connection found in the app.config or web.config file can be a normal database connection
///             string (not a special Entity Framework connection string) in which case the DbContext will use Code First.
 ///             However, if the connection found in the config file is a special Entity Framework connection string, then the
 ///             DbContext will use Database/Model First and the model specified in the connection string will be used.
 ///             An existing or explicitly created DbConnection can also be used instead of the database/connection name.
 ///             A <see cref="T:System.Data.Entity.DbModelBuilderVersionAttribute"/> can be applied to a class derived from DbContext to set the
 ///             version of conventions used by the context when it creates a model. If no attribute is applied then the
 ///             latest version of conventions will be used.