Entity Framework Exception "The underlying provider failed on Open"

Question

I have created a windows service which listen to a TCP/IP port and save received data in database using Entity Framework. Most of the time it works fine but some time its throwing an exception "The underlying provider failed on open." on save data in database. Here is my exception details:

    Exception: 2/27/2014 10:31 AM:
    The underlying provider failed on Open.
     at System.Data.Entity.Core.EntityClient.EntityConnection.Open()
     at System.Data.Entity.Core.Objects.ObjectContext.EnsureConnection()
     at System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[T](Func`1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess)
     at System.Data.Entity.Core.Objects.ObjectQuery`1.<>c__DisplayClassb.<GetResults>b__9()
     at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func`1 operation)
     at System.Data.Entity.Core.Objects.ObjectQuery`1.GetResults(Nullable`1 forMergeOption)
    at System.Data.Entity.Core.Objects.ObjectQuery`1.<System.Collections.Generic.IEnumerable<T>.GetEnumerator>b__0()
     at System.Lazy`1.CreateValue()
     at System.Lazy`1.LazyInitValue()
     at System.Lazy`1.get_Value()
     at System.Data.Entity.Internal.LazyEnumerator`1.MoveNext()
     at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source)
     at System.Data.Entity.Core.Objects.ELinq.ObjectQueryProvider.<GetElementFunction>b__1[TResult](IEnumerable`1 sequence)
     at System.Data.Entity.Core.Objects.ELinq.ObjectQueryProvider.ExecuteSingle[TResult](IEnumerable`1 query, Expression queryRoot)
     at System.Data.Entity.Core.Objects.ELinq.ObjectQueryProvider.System.Linq.IQueryProvider.Execute[TResult](Expression expression)
    at System.Data.Entity.Internal.Linq.DbQueryProvider.Execute[TResult](Expression expression)
    at System.Linq.Queryable.FirstOrDefault[TSource](IQueryable`1 source)
    at Service.DemoService.Save(String received, TcpClient client)

What is the thing behind this exception and how to resolve it?

Check your connection string – Bhupendra Shukla Feb 27 '14 at 05:49 — Bhupendra Shukla, Feb 27 '14 at 05:49
My connection string `` – Rajesh Puniya Feb 27 '14 at 05:57 — Rajesh Puniya, Feb 27 '14 at 05:57

score 7 · Accepted Answer · edited Sep 06 '15 at 09:30

7

Usually, when working with Entity Framework you'll need to enable the multiple active result sets option in your connection string by setting MultipleActiveResultSets to true as follows.

<add name="conn" 
  connectionString="
    Data Source=.\;
    Initial Catalog=TDB;
    UID=admin123;
    PWD=123;
    MultipleActiveResultSets=True"
  providerName="System.Data.SqlClient" />

Verify that it solves your problem.

edited Sep 06 '15 at 09:30

Konrad Viltersten

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answered Feb 27 '14 at 08:25

Alberto

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6

MultipleActiveResultSets is already set to True in my config but I still get this error. – Raj Chaurasia Oct 11 '18 at 13:55

score 0 · Answer 2 · answered Dec 19 '14 at 12:13

0

Check whether you SQL Server is running or not. Just Open Task Manager and Goto Services, Click on Services button below and check whether SQL Server is running or not.

answered Dec 19 '14 at 12:13

user3139697

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score 0 · Answer 3 · answered Oct 11 '18 at 14:03

0

In my case, the issue was that the account which I was using to connect to SQL server was not added to app pool identity. Once I added the account 'domain\username' to app pool, it started working.

answered Oct 11 '18 at 14:03

Raj Chaurasia

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score 0 · Answer 4 · answered Oct 29 '20 at 19:57

0

Change integrated security= False ; MultipleActiveResultSets=True in your connection string , it should be work.

answered Oct 29 '20 at 19:57

B.Nishan

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score 0 · Answer 5 · answered Sep 13 '21 at 20:34

0

I had this error but I solved it by Opening Task Manager, Go to Services and checking if my SQL Server is running or not. Your Sql server should be running.

answered Sep 13 '21 at 20:34

Gomotso Sejentu

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Hi Gomotso - I think your answer is the same as the one given by user3139697. – pettys Sep 13 '21 at 21:50

Entity Framework Exception "The underlying provider failed on Open"

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