Web應用程序在Web服務器上工作，但從其他機器給出錯誤

Question

我有一個ASP.Net MVC 3應用程序。我爲它創建了一個安裝程序並安裝在我的網絡服務器上。

當我從網絡瀏覽器訪問應用程序"http://localhost/myapp"時，它工作。

但當我從另一臺機器，試圖像"http://mywebserver/myapp"它給了一個錯誤：

The model item passed into the dictionary is of type 'System.Web.Mvc.HandleErrorInfo', but this dictionary requires a model item of type myapp.Models.ErrorModel'.`

Answer 1

按： http://blogs.msdn.com/b/dataaccesstechnologies/archive/2012/08/09/error-quot-the-underlying-provider-failed-on-open-quot-in-entity-framework-application.aspx

這可能是在新服務器上權限問題等

 
Solution 1:
 

In the existing connection string to remove the 「user Instance=true」 and it works.
 

Probable cause of the issue could be as below: 
The user instance cannot attach the database because the user does not have the required permissions. The user instance executes in the context of the user who opened the connection—not the normal SQL Server service account. The user who opened the user instance connection must have write permissions on the .mdf and .ldf files that are specified in the AttachDbFilename option of the connection string.
 

Another common issue is when you open a database file successfully when the database is attached to the SQL Server Express instance, but fails when you try to open it from the Visual Studio IDE. This might occur because the SQL Server Express instance is running as "NT AUTHORITY\NETWORK SERVICE," while the IDE is running as windows account. Therefore, the permissions may not work.
 

A variation of this issue is when the user that opens the user instance connection has read permissions on the database files but does not have write permissions. If you get a message saying that the database is opened as read only, you need to change the permissions on the database file.
 

The other main issue with user instances occurs because SQL Server opens database files with exclusive access. This is necessary because SQL Server manages the locking of the database data in its memory. Thus, if more than one SQL Server instance has the same file open, there is the potential for data corruption. If two different user instances use the same database file, one instance must close the file before the other instance can open it. There are two common ways to close database files, as follows.
 

User instance databases have the Auto Close option set so that if there are no connections to a database for 8-10 minutes, the database shuts down and the file is closed. This happens automatically, but it can take a while, especially if connection pooling is enabled for your connections.
 

Detaching the database from the instance by calling sp_detach_db will close the file. This is the method Visual Studio uses to ensure that the database file is closed when the IDE switches between user instances. For example, you are using the IDE to design a data-enabled Web page. You press F5 to run the application. The IDE detaches the database so that ASP.NET can open the database files. If you leave the database attached to the IDE and try to run the ASP page from your browser, ASP.NET cannot open the database because the file is still in use by the IDE.