.mdf文件不响应SqlCommand.ExecuteNonQuery

Question

I have a weird problem with my local database. I added it as a .mdf file, and created 2 tables in it.

I tested the connection and the message box states that the connection is working properly.

The problem appears when I try to insert data into that database from my C# application. I tried 2 different ways:

1. By using SqlCommand.ExecuteNonQuery("INSERT INTO ....")
2. By using .dbml file (Linq-to-SQL) datacontext

When I try to insert data, no error is thrown, but no data is inserted into the database either. What could be the problem?

I'm using C# in VS 2010 and SQL Server 2005 to make my application

Answer 1

most perceived problems with MDF files tend to boil down to one of:

• what file have I actually opened?
• is my build/run process actually copying over that file every time I run the application?
• do I have gratuitous error-handling that is swallowing an exception?

Check your connection string, and look in the execution folder (not the project folder), until you are very sure which file is being opened. It should get updated after your work (make sure you dispose the connection etc properly).

Also: try fetching the data in a new data-context immediately after the insert, so see if it made it in or not.