Unable to update database .MDF is Read Only

问题:

I have a local DB that I have in an application. When I install it on another machine I get the error

Unable to update database.. .mdf is read only.

I was able to get around it by editing my permissions on the .mdf and log file themselves. I did some research and noticed that I may want to install the database to a shared folder. However, I am not sure how to do that and the answers I did come across did not make a whole lot of sense to be.

 //My connection string
 SqlConnection con = new SqlConnection(@"Data Source=(LocalDB)\v11.0;AttachDbFilename=|DataDirectory|AssetDatabase.mdf;Integrated Security=True");

Any guidance would be greatly appreciated. I am learning.

回答1:

The MDF file would be readonly either because the readonly file attribute flag is set, in which case you have to unset it, or another program has the MDF file locked as readonly. Are you running a version of SQL server that is using that file?

I've never seen a connection to the MDF file directly, usually it's done via the server, and the server will manage all the IO for the MDF file.

E.g. a typical connection string for SQL Server:

Database=<dbname>;Server=<servername>;MultipleActiveResultSets=True;Connection Timeout=10;User Id=<username>;Password=<password>;

Additional links:

1) Failed to update .mdf database because the database is read-only (Windows application)

2) Failed to update database because it is read-only

3) Failed to update database "*.mdf" because read only EntityFramework

4) http://www.codeproject.com/Questions/183758/Failed-to-update-mdf-database-because-the-database

回答2:

First stop the SQLEXPRESS service from local-Services menu and then try to move and connect the database again by attaching database option in SQLEXPRESS. it should work. it works for me. :)

回答3:

1. Just go to the program files and find the folder of the installed program.
2. Just right click the .mdf file in the folder and click PROPERTIES.
3. In PROPERTIES TAB -> SECURITY -> you'll see Group or Usernames.
4. In that select the User to which u want to give Access to the file.
5. If for that user the PERMISSION is not set to FULL CONTROL.
6. TO CHANGE PERMISSIONS -> CLICK EDIT.
7. Now the Group or Username box will open.
8. In that Select The User -> Select FULL CONTROL in Permission Box.
9. Now follow the steps for the log file too. IF Needed.

OR

Just install your application in different folder other than ProgramFile(x86)

回答4:

if your database file on the C volume, try to move the .mfd file to D volume