EF 5 + SQL Server CE 4：如何为数据库文件指定自定义位置？ [英] EF 5 + SQL Server CE 4: How to specify custom location for database file?

问题描述

我正在开发一个需要小型本地数据库的客户端系统。
我想避免安装SQL Server Express，并决定使用SQL Server 4。

I am developing a client system that needs a small local database. I want to avoid installation of SQL Server Express and have decided to go with SQL Server 4.

我使用Entity Framework 5进行数据访问，并创建了自定义上下文。
开发过程中一切正常，我可以使用app.config设置特定文件位置或动态 Data Source = | DataDirectory | \MyDatabase.sdf 。

I use Entity Framework 5 for data access and have created my custom context. Everything works fine in development where I can use app.config to either set specific file location or dynamic Data Source=|DataDirectory|\MyDatabase.sdf.

但是在部署时，我希望数据库位于用户文档文件夹中：

But on deploy I want the database to be located in the users documents folder:

\My Documents\ApplicationName\MyDatabase.sdf

我该怎么做？

我真正需要的只是能够在代码中设置自定义连接字符串！

All I need is actually to be able to set custom connection string in code!

这就是到目前为止，我尝试过：

This is what I tried so far:

private MyApplicationDataContext(string connectionString)
    : base(connectionString)
{
}

public static MyApplicationDataContext CreateInstance()
{
    var directory = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
    var path = Path.Combine(directory, @"ApplicationName\MyDatabase.sdf");

    //var connectionString = string.Format("provider=System.Data.SqlServerCe.4.0;provider connection string=\"Data Source={0}\"", path);
    var connectionString = string.Format("Data Source={0}", path);

    return new MyApplicationDataContext(connectionString);
}

如您所见，我尝试了两种连接字符串，但都导致异常。

As you can see I tried two kinds of connection strings but both caused exceptions.

不支持关键字： provider。

Keyword not supported: 'provider'.

和

提供程序未返回ProviderManifestToken字符串。

The provider did not return a ProviderManifestToken string.

推荐答案

啊，我终于明白了！

如果其他人有，我会提供调整后的代码同样的问题。
诀窍是在Database.DefaultConnectionFactory

I include the adjusted code if someone else has the same problem. The trick was to set the connection string on the Database.DefaultConnectionFactory

    private MyApplicationDataContext()
    { }

    public static MyApplicationDataContext CreateInstance()
    {
        var directory = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
        var path = Path.Combine(directory, @"ApplicationName\MyDatabase.sdf");

        // Set connection string
        var connectionString = string.Format("Data Source={0}", path);
        Database.DefaultConnectionFactory = new SqlCeConnectionFactory("System.Data.SqlServerCe.4.0", "", connectionString);

        return new MyApplicationDataContext();
    }

这篇关于EF 5 + SQL Server CE 4：如何为数据库文件指定自定义位置？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！