An attempt to attach an auto-named database for file

 1 Server Error in ‘/‘ Application.
 2 An attempt to attach an auto-named database for file F:\cs\office\ReadWriterOffice\ReadWriterOffice\App_Data\Database.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share.
 3 
 4 Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
 5 
 6 Exception Details: System.Data.SqlClient.SqlException: An attempt to attach an auto-named database for file F:\cs\office\ReadWriterOffice\ReadWriterOffice\App_Data\Database.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share.
 7 
 8 Source Error:
 9 
10 Line 95:             DB db = new DB("DBConnectionString");
11 Line 96:             using (SqlConnection conn = new SqlConnection(db.ConnectionString)) {
12 Line 97:                 conn.Open();
13 Line 98:                 using (SqlCommand cmd = conn.CreateCommand()) {
14 Line 99:                     cmd.CommandText = sql;
15 
16 
17 Source File: F:\cs\office\ReadWriterOffice\ReadWriterOffice\Samples\TransmitLonLa.aspx.cs    Line: 97
18 
19 Stack Trace:
20 
21 [SqlException (0x80131904): An attempt to attach an auto-named database for file F:\cs\office\ReadWriterOffice\ReadWriterOffice\App_Data\Database.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share.]
22    System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) +5009598
23    System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning() +234
24    System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) +2275
25    System.Data.SqlClient.SqlInternalConnectionTds.CompleteLogin(Boolean enlistOK) +35
26    System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, Boolean ignoreSniOpenTimeout, TimeoutTimer timeout, SqlConnection owningObject) +183
27    System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(ServerInfo serverInfo, String newPassword, Boolean redirectedUserInstance, SqlConnection owningObject, SqlConnectionString connectionOptions, TimeoutTimer timeout) +239
28    System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(SqlConnection owningObject, TimeoutTimer timeout, SqlConnectionString connectionOptions, String newPassword, Boolean redirectedUserInstance) +195
29    System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, Object providerInfo, String newPassword, SqlConnection owningObject, Boolean redirectedUserInstance) +232
30    System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection) +185
31    System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnection owningConnection, DbConnectionPool pool, DbConnectionOptions options) +33
32    System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject) +524
33    System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject) +66
34    System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject) +479
35    System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) +108
36    System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) +126
37    System.Data.SqlClient.SqlConnection.Open() +125
38    ReadWriterOffice.Samples.TransmitLonLa.ExportExcel() in F:\cs\office\ReadWriterOffice\ReadWriterOffice\Samples\TransmitLonLa.aspx.cs:97
39    ReadWriterOffice.Samples.TransmitLonLa.Page_Load(Object sender, EventArgs e) in F:\cs\office\ReadWriterOffice\ReadWriterOffice\Samples\TransmitLonLa.aspx.cs:24
40    System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +14
41    System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +35
42    System.Web.UI.Control.OnLoad(EventArgs e) +91
43    System.Web.UI.Control.LoadRecursive() +74
44    System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2207
45 
46  
47 
48 Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.1