Cannot attach the file mdf as database

Question

Basically I ve followed a tutorial and decided to delete the  mdf file afterwards   Now whenever I try to run the application I get the following error  the title of this thread   The code where I get the error is shown below  ASP NET MVC 4    OdeToFoodDB db   new OdeToFoodDB     public ActionResult Index         var model   db Restaurants ToList        return View model       My connection string is the following    lt add name  DefaultConnection        connectionString  Data Source  LocalDb  v11 0 Initial Catalog OdeToFoodDb Integrated Security SSPI AttachDBFilename  DataDirectory  OdeToFoodDb mdf        providerName  System Data SqlClient    gt    I ve tried looking at the SQL Server Object Explorer but it looks the following   Also  in Server Explorer I don t see any data connections   And when I try to add a new connection in Server Explorer I don t see any databases named OdeToFoodDb   Sorry for this wide question but I m new to Entity Framework and don t quite get what s wrong here

User · Answer

I had the same error while following the tutorial on  Getting Started with ASP NET MVC 5   Microsoft Docs   I was on Visual Studio 2015  I opened View-  SQL Server Object Explorer and deleted the database named after the tutorial  then it could work  see Delete  mdf file from app data causes exception cannot attach the file as database

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Strangely  for the exact same issue  what helped me was changing the   to  v11 0  in the following section of the config    lt defaultConnectionFactory type  System Data Entity Infrastructure LocalDbConnectionFactory  EntityFramework  gt         lt parameters gt           lt parameter value  v11 0    gt         lt  parameters gt

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In my case removing Initail Cataloge      from connection string resolved the issue

User · Answer

Remove this line from the connection string that should do it     AttachDbFilename  DataDirectory whateverurdatabasenameis-xxxxxxxxxx mdf

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Cannot attach the file  C  Github TestService TestService App data TestService mdf  as database  TestService   When you meet the above error message  Please do the following steps    Open SQL Server Object Explorer Click refresh button  Expand  localdb  MSSQLLocalDB SQL Server 12 x xxxxx - xxxxx xxxx  Expand Database Please remove existed same name database Click right button and then delete Go back to your Package Manage Console Update-Database

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Take a look at this  Entity Framework don t create database     I would try giving the database a   different name   Sometimes you can run into problems with SQL Express   when trying to create a database with the same name a second time     There is a way to fix this using SQL Server Management Studio but it s   generally easier to just use a different database name    Edit This answer was accepted because it confirms the bug and the workaround used by OP  renaming database could help   I totally agree that renaming the database is not really an acceptable way  and does not totally solve the issue  Unfortunatly I didn t check the other ways to really solve it in SSMS

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Just change database name from web config project level file and then update database   connectionString   Data Source   LocalDb  MSSQLLocalDB AttachDbFilename  quot  DataDirectory  aspnet-Project name-20180413070506 mdf quot  Initial Catalog  quot aspnet--20180413070506 quot  Integrated  Change the bold digit to some other number   connectionString   Data Source   LocalDb  MSSQLLocalDB AttachDbFilename  quot  DataDirectory  aspnet-Project name-20180413070507 mdf quot  Initial Catalog  quot aspnet--20180413070507 quot  Integrated

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Recreate your database   Do not delete it and your app should continue to work

User · Answer

I didn t read all the responses  but if your  mdf file is NOT part of the SQL installation path  like C  Temp  then the SQL Database Engine service account s  will not have permission to create and write to the  ldf file or even read the  mdf file   The solution is you have to give file system permissions to the SQL Server database engine service account that runs the SQL instance service   So for me  I gave permissions full control via Windows Explorer to my C  Temp path that contained my  mdf file for the NT Service MSSQL SQLEXPRESS01 and NT Service MSSQL MSSQL2016 accounts   Here is a Microsoft article that details this very issue

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We just ran into this ourselves when running dotnet ef database update using ASP Net Core 2 1  looks like relative paths aren t supported with AttachDbFileName     System Data SqlClient SqlException  0x80131904   Cannot attach the file    OurDbName mdf  as database  OurDbName     Just wanted to express that here for other people who might be bumping into this   The  fix  is use absolute paths   See also  https   github com aspnet EntityFrameworkCore pull 6446

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I found that commenting out the context section used to initialise the database resolved the problem  Havnt had time to find out what was wrong with the seeding statements yet  but removing the seeding resolved the problem

User · Answer

From Package Manager Console run   sqllocaldb exe stop v11 0  sqllocaldb exe delete v11 0 Run your project Register a user

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As per  davide-icardi  remove the  Initial Catalog xxx   from web config  but also check for your azure publish profile file to remove it from here too    YourAspNetProject path  Properties PublishProfiles YourAspNetProjectName  pubxml   lt PublishDatabaseSettings gt     lt Objects xmlns    gt       lt ObjectGroup Name  YourAspNetProjectName  Order  1  Enabled  True  gt         lt Destination Path  Data Source AzureDataBaseServer Initial Catalog azureDatabase db User ID AzureUser db sa AzureDataBaseServer Password test    gt         lt Object Type  DbCodeFirst  gt           lt Source Path  DBMigration  DbContext  YourAspNetProjectName Models ApplicationDbContext  YourAspNetProjectName  MigrationConfiguration  YourAspNetProjectName Migrations Configuration  YourAspNetProjectName  Origin  Configuration    gt         lt  Object gt       lt  ObjectGroup gt     lt  Objects gt   lt  PublishDatabaseSettings gt

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I think that for SQL Server Local Db you shouldn t use the Initial Catalog property  I suggest to use    lt add name  DefaultConnection        connectionString  Data Source  LocalDb  v11 0 Integrated Security SSPI AttachDBFilename  DataDirectory  OdeToFoodDb mdf        providerName  System Data SqlClient    gt    I think that local db doesn t support multiple database on the same mdf file so specify an initial catalog is not supported  or not well supported and I have some strange errors

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I had the same error  Weird thing was  I had one new project form scratch  there it worked perfectly and another  much bigger project  where I always ran into that error message   The perfecrtly working project  nearly  always creates the database  indluding the files  automatically  It can be any command  read  write  update  The files get created  Of course it uses  DropCreateDatabaseIfModelChanges   There is only one case  when it gets troubled  IF the mdf is auto-created and you delete the mdf and log file  Then that was about it  Say good-bye to your autocreation     The only way I found to fix it was like mentioned   sqllocaldb stop v11 0  amp  sqllocaldb delete v11 0   After that  everything is back to normal  and all other Databases handled by LocalDB also gone     EDIT  That was not true  I just tried it and the v11 0 gets automatically recreated and all mdfs stay available  I have not tried with  non file based  LocalDBs   The confusing thing is  I also got this error if something else was wrong  So my suggestion is  if you want to make sure your DB-Setup is sound and solid  Create a new solution project from scratch  use the most basic DB commands  Add an entity  show all entities  delete all entities  and see if it works    If YES  the problem is somewhere in the abyss of VS2013 config and versioning and nuget and stuff   IF NO  you have a problem with your LocalDB installation   For anyone who really wants to understand what s going on in EF  and I am still not sure if I do  -    http   odetocode com Blogs scott archive 2012 08 14 a-troubleshooting-guide-for-entity-framework-connections-amp-migrations aspx  P S   Nudge me if you need the running example project

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Ran into the similar problem not exactly the same  A case of Database already existed the issue was solved by following code    x000D   x000D   lt add name  DefaultConnection  connectionString  Data Source   AttachDbFilename  DataDirectory  aspnet-EjournalParsing-20180925054839 mdf Initial Catalog aspnet-EjournalParsing-20180925054839 Integrated Security True  x000D        providerName  System Data SqlClient    gt  x000D   x000D   x000D

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If you happen to apply migrations already this may fix it   Go to your Web config and update your connection string based on your migration files   Data Source  LocalDb  MSSQLLocalDB AttachDbFilename  DataDirectory  aspnet-GigHub-201802102244201 mdf Initial Catalog aspnet-GigHub-201802102244201    The datestrings should match the first numbers on your Migrations

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I recently ran into the same problem  Here is one thing to check   in visual studio there are three place we should check and remove the database    1  Solution Explorer s App Data folder 2  Server Explorer s Data Connection menu 3  SQL Server Object Explorer   When I delete database from the first two point  the error still occurs  So  I needed to delete the database from the SQL Server Object Explorer as well   Then I could easily run the  update-database  command without error   Hope this helps

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I have faced the same issue  The following steps in VS 2013 solved the problem for me    In Server Explorer add new Connect to Database Select Microsoft SQL Server Database File as Data source Choose database filename as it should be in according to connection string in your web config New database file was created and two database connections was appeared in Server Explorer   MyDatabaseName  and  MyDatabaseName  MyProjectName   Delete one connection  I ve deleted  MyDatabaseName

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Ran into this issue  Caused in my case by deleting the  mdf while iispexress was still running and therefor still using the DB  Right click on iisexpress in system tray and click exit THEN delete the MDF to prevent this error from actually occurring   To fix this error simply within VS right click the App-Data folder add new item   SQL Server Database  Name   use the database name provided by the update-database error  Click Add

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You already have an old copy of that database installed in Server Explorer  So its a simple naming collision in the Server Object Explorer   SQL server  You likely created the same database Catalog Name already before you decided to move it to the Apps Data folder  So that Database name already exists and just needs to be deleted   Just go into Visual Studio   View   SQL Server Object Explorer and delete the old database name and its connection  Retry your app again and it should install the  mdf file in App Data and create the same exact database again in the Server Explorer

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To fix this using SQL SERVER Management Studio Your problem  You get an error such as  Cannot attach the file  YourDB mdf  as database  YourConnStringNamedContext   Reason  happens because you deleted the backing files  mdf  ldf without actually deleting the database within the running instance of SqlLocalDb  re-running the code in VS won t help because you cannot re-create a DB with the same name  and that s why renaming works  but leaves the old phantom db name lying around   The Fix  I am using VS2012  adopt similarly for a different version  Navigate to below path and enter  c  program files microsoft sql server 110 Tools Binn gt sqllocaldb info  Above cmd shows the instance names  including  v11 0  If the instance is already running  enter at the prompt  sqllocaldb info v11 0  Note the following info Owner  YourPCName Username   State  Running   Instance pipe name  np    pipe LOCALDB 12345678 tsql query   where 123456789 is some random alphanumeric If State is not running or stopped  start the instance with  sqllocaldb start v11 0  and extract same info as above  In the SS Management Studio  Connect  dialog box enter  server name  np    pipe LOCALDB 12345678 tsql query auth   Windows auth user name   same as Owner  it is grayed out for Win  auth    Once connected  find the phantom DB which you deleted  e g  YourDB mdf should have created a db named YourDB   and really delete it  Done  Once it s gone  VS EF should have no problem re-creating it

[.net] Cannot attach the file *.mdf as database

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