Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
242 views
in Technique[技术] by (71.8m points)

c# - Entity Framework giving exception : "The underlying provider failed on Open."

I have a test. What happens is that whenever test1 is executed first, test2 fails with the message:

"System.Data.EntityException : System.Data.EntityException : the underlying provider failed on open. cannot open database "DBEntities" requested by the login. The login failed.".

and whenever test2 is executed first, test1 fails with the same message.

I've been at this for the past 3 days.

[TestClass]
class MyTestClass 
{

    DBEntities db;

    [TestInitialize]
    public void Initializer()
    {
       db = new DBEntities(); 
    }

    [TestMethod]
    public void test1()
    {
       db.Books.Add(new Book{ ...});
       db.SaveChanges();

    }

    [TestMethod]
    public void test2()
    {
       db.Books.Add(new Book{ ...});
       db.SaveChanges();
    }


    [TestCleanup]
    public void Clean()
    {
       db.Dispose(); 
    }

}

Here's an excerpt of the DBEntities class :

public class DBEntities : DbContext
{
    public DbSet<Books> TheBooks{get;set;}
    ...
}

After running a profiler, I noticed this message:

"Login failed for user. Reason: failed to open the explicitly specified database."

after a lot of lockAcquired and lockReleased statements.

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

Might the issue be connection pooling? Would the SQL provider try to preserve the connection between tests, even though the EF object is disposed? In that case would it be having an issue w/ multiple connections to the same DB by the same user?

Try explicitly closing the connection in your cleanup:

db.Database.Connection.Close();

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...