title: SQLException when putting query in IEnumerable
body: <p>I am accessing a database and doing some queries with LINQ.</p>
  
  <p>Whenever I try to put the query result in an IEnumerable I get an SQLException.</p>
  
  <p>I tried putting it in a var type first then putting it in an IEnumerable or even a List using the .ToList() method, with the same SQLException.</p>
  
  <p>I'm guessing it has to do with the way I'm connecting to the database. However I have absolutely no idea how to fix this.</p>
  
  <p>The table is populated with 3 records.</p>
  
  <p>What am I missing?</p>
  
  <p>This is the following code that has to do with the query:</p>
  
  <pre><code>public static AppointmentDBDataContext db = new AppointmentDBDataContext("Visual Studio 2013/Projects/AppointmentBookingSystem/AppointmentBookingSystem/AppointmentDB.mdf");    
  public IEnumerable&lt;Item&gt; getAll()
          {
              Console.WriteLine("Query");
              IEnumerable&lt;Item&gt; list = (from i in db.Items
                                          select i);
              Console.WriteLine("Done Query");
              return list;
          }
  </code></pre>
  
  <p>This is the exception thrown:</p>
  
  <pre><code>    A first chance exception of type 'System.Data.SqlClient.SqlException' occurred in System.Data.dll
  System.Transactions Critical: 0 : &lt;TraceRecord xmlns="http://schemas.microsoft.com/2004/10/E2ETraceEvent/TraceRecord" Severity="Critical"&gt;&lt;TraceIdentifier&gt;http://msdn.microsoft.com/TraceCodes/System/ActivityTracing/2004/07/Reliability/Exception/Unhandled&lt;/TraceIdentifier&gt;&lt;Description&gt;Unhandled exception&lt;/Description&gt;&lt;AppDomain&gt;AppointmentBookingSystem.vshost.exe&lt;/AppDomain&gt;&lt;Exception&gt;&lt;ExceptionType&gt;System.Data.SqlClient.SqlException, System.Data, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089&lt;/ExceptionType&gt;&lt;Message&gt;A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)&lt;/Message&gt;&lt;StackTrace&gt;   at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
     at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose)
     at System.Data.SqlClient.TdsParser.Connect(ServerInfo serverInfo, SqlInternalConnectionTds connHandler, Boolean ignoreSniOpenTimeout, Int64 timerExpire, Boolean encrypt, Boolean trustServerCert, Boolean integratedSecurity, Boolean withFailover, SqlAuthenticationMethod authType)
     at System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean ignoreSniOpenTimeout, TimeoutTimer timeout, Boolean withFailover)
     at System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString connectionOptions, SqlCredential credential, TimeoutTimer timeout)
     at System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(TimeoutTimer timeout, SqlConnectionString connectionOptions, SqlCredential credential, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance)
     at System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, SqlCredential credential, Object providerInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString userConnectionOptions, SessionData reconnectSessionData, DbConnectionPool pool, String accessToken)
     at System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions)
     at System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnectionPool pool, DbConnection owningObject, DbConnectionOptions options, DbConnectionPoolKey poolKey, DbConnectionOptions userOptions)
     at System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
     at System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
     at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConnectionInternal&amp;amp;amp; connection)
     at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal&amp;amp;amp; connection)
     at System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal&amp;amp;amp; connection)
     at System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
     at System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
     at System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource`1 retry)
     at System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry)
     at System.Data.SqlClient.SqlConnection.Open()
     at System.Data.Linq.SqlClient.SqlConnectionManager.UseConnection(IConnectionUser user)
     at System.Data.Linq.SqlClient.SqlProvider.get_IsSqlCe()
     at System.Data.Linq.SqlClient.SqlProvider.InitializeProviderMode()
     at System.Data.Linq.SqlClient.SqlProvider.System.Data.Linq.Provider.IProvider.Execute(Expression query)
     at System.Data.Linq.DataQuery`1.System.Collections.Generic.IEnumerable&amp;amp;lt;T&amp;amp;gt;.GetEnumerator()
     at AppointmentBookingSystem.DatabaseExplorer.button1_Click(Object sender, EventArgs e) in c:\Users\Kim\Documents\Visual Studio 2013\Projects\AppointmentBookingSystem\AppointmentBookingSystem\DatabaseExplorer.cs:line 28
     at System.Windows.Forms.Control.OnClick(EventArgs e)
     at System.Windows.Forms.Button.OnClick(EventArgs e)
     at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
     at System.Windows.Forms.Control.WmMouseUp(Message&amp;amp;amp; m, MouseButtons button, Int32 clicks)
     at System.Windows.Forms.Control.WndProc(Message&amp;amp;amp; m)
     at System.Windows.Forms.ButtonBase.WndProc(Message&amp;amp;amp; m)
     at System.Windows.Forms.Button.WndProc(Message&amp;amp;amp; m)
     at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message&amp;amp;amp; m)
     at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message&amp;amp;amp; m)
     at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
     at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG&amp;amp;amp; msg)
     at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
     at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
     at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
     at System.Windows.Forms.Application.Run(Form mainForm)
     at AppointmentBookingSystem.Program.Main() in c:\Users\Kim\Documents\Visual Studio 2013\Projects\AppointmentBookingSystem\AppointmentBookingSystem\Program.cs:line 19
     at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
     at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
     at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
     at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
     at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
     at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
     at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
     at System.Threading.ThreadHelper.ThreadStart()&lt;/StackTrace&gt;&lt;ExceptionString&gt;System.Data.SqlClient.SqlException (0x80131904): A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)
     at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
     at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose)
     at System.Data.SqlClient.TdsParser.Connect(ServerInfo serverInfo, SqlInternalConnectionTds connHandler, Boolean ignoreSniOpenTimeout, Int64 timerExpire, Boolean encrypt, Boolean trustServerCert, Boolean integratedSecurity, Boolean withFailover, SqlAuthenticationMethod authType)
     at System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean ignoreSniOpenTimeout, TimeoutTimer timeout, Boolean withFailover)
     at System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString connectionOptions, SqlCredential credential, TimeoutTimer timeout)
     at System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(TimeoutTimer timeout, SqlConnectionString connectionOptions, SqlCredential credential, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance)
     at System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, SqlCredential credential, Object providerInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString userConnectionOptions, SessionData reconnectSessionData, DbConnectionPool pool, String accessToken)
     at System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions)
     at System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnectionPool pool, DbConnection owningObject, DbConnectionOptions options, DbConnectionPoolKey poolKey, DbConnectionOptions userOptions)
     at System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
     at System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
     at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConnectionInternal&amp;amp;amp; connection)
     at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal&amp;amp;amp; connection)
     at System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal&amp;amp;amp; connection)
     at System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
     at System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
     at System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource`1 retry)
     at System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry)
     at System.Data.SqlClient.SqlConnection.Open()
     at System.Data.Linq.SqlClient.SqlConnectionManager.UseConnection(IConnectionUser user)
     at System.Data.Linq.SqlClient.SqlProvider.get_IsSqlCe()
     at System.Data.Linq.SqlClient.SqlProvider.InitializeProviderMode()
     at System.Data.Linq.SqlClient.SqlProvider.System.Data.Linq.Provider.IProvider.Execute(Expression query)
     at System.Data.Linq.DataQuery`1.System.Collections.Generic.IEnumerable&amp;amp;lt;T&amp;amp;gt;.GetEnumerator()
     at AppointmentBookingSystem.DatabaseExplorer.button1_Click(Object sender, EventArgs e) in c:\Users\Kim\Documents\Visual Studio 2013\Projects\AppointmentBookingSystem\AppointmentBookingSystem\DatabaseExplorer.cs:line 28
     at System.Windows.Forms.Control.OnClick(EventArgs e)
     at System.Windows.Forms.Button.OnClick(EventArgs e)
     at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
     at System.Windows.Forms.Control.WmMouseUp(Message&amp;amp;amp; m, MouseButtons button, Int32 clicks)
     at System.Windows.Forms.Control.WndProc(Message&amp;amp;amp; m)
     at System.Windows.Forms.ButtonBase.WndProc(Message&amp;amp;amp; m)
     at System.Windows.Forms.Button.WndProc(Message&amp;amp;amp; m)
     at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message&amp;amp;amp; m)
     at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message&amp;amp;amp; m)
     at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
     at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG&amp;amp;amp; msg)
     at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
     at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
     at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
     at System.Windows.Forms.Application.Run(Form mainForm)
     at AppointmentBookingSystem.Program.Main() in c:\Users\Kim\Documents\Visual Studio 2013\Projects\AppointmentBookingSystem\AppointmentBookingSystem\Program.cs:line 19
     at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
     at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
     at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
     at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
     at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
     at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
     at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
     at System.Threading.ThreadHelper.ThreadStart()
  </code></pre>