如何从C＃和SQL创建受用户名和密码保护的MS Access 2007文件？

Question

I don't know much about OleDB and I need some information on how to create a MS Access 2007 file as password protected. This is a piece of code which use User Id=admin; Password= User Id=admin; Password= but it gives me an error while trying to save saying: Cannot start your application. The workgroup information file is missing or opened exclusively by another user. Cannot start your application. The workgroup information file is missing or opened exclusively by another user.

EDIT: Now I have error: Cannot open the MS Office Access database engine workgroup information file

I have figured out that problems lay in the SQL command. What SQL command should I be using? This command creates a problem, and I can't figure out why. I have used similar syntax from the link that person provided in the comment.

    try
    {
        objOleDbConnection.Open();
        objOleDbCommand.CommandText = 
            "ALTER USER " + storedAuth.UserName + 
            " PASSWORD [" + storedAuth.Password + "] []";
        objOleDbCommand.ExecuteNonQuery();
    }

I could use following code, but what about user name?

objOleDbCommand.CommandText = "ALTER DATABASE PASSWORD " + storedAuth.Password + "[]";

EDITTED changed the code what I have now:

    private void sfdNewFile_FileOk(object sender, System.ComponentModel.CancelEventArgs e)
    {
        // Creating a ADOX object needed to create
        // new MS Access file.
        ADOX.Catalog createMSFile = new ADOX.Catalog();

        createMSFile.Create("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" +
            sfdNewFile.FileName);

        Table nTable = new Table();
        nTable.Name = "PersonData";
        nTable.Columns.Append("DataID", DataTypeEnum.adInteger, 40);
        nTable.Columns.Append("Type", DataTypeEnum.adVarWChar, 40);
        nTable.Columns.Append("URL", DataTypeEnum.adVarWChar, 40);
        nTable.Columns.Append("SoftwareName", DataTypeEnum.adVarWChar, 40);
        nTable.Columns.Append("SerialCode", DataTypeEnum.adVarWChar, 40);
        nTable.Columns.Append("UserName", DataTypeEnum.adVarWChar, 40);
        nTable.Columns.Append("Password", DataTypeEnum.adVarWChar, 40);

        createMSFile.Tables.Append(nTable);

        // It is importnat to release COM object, in this very order
        // otherwise we eill end up with an error.
        System.Runtime.InteropServices.Marshal.FinalReleaseComObject(nTable);
        System.Runtime.InteropServices.Marshal.FinalReleaseComObject(createMSFile.Tables);
        System.Runtime.InteropServices.Marshal.FinalReleaseComObject(createMSFile.ActiveConnection);
        System.Runtime.InteropServices.Marshal.FinalReleaseComObject(createMSFile);

        OleDbConnection objOleDbConnection = new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;" +
                "Data Source=" + sfdNewFile.FileName);
        OleDbCommand objOleDbCommand = objOleDbConnection.CreateCommand();

        try
        {
            objOleDbConnection.Open();
            objOleDbCommand.CommandText = "ALTER DATABASE PASSWORD [" + storedAuth.Password + "] []";
            objOleDbCommand.ExecuteNonQuery();
        }
        catch (Exception ex)
        {
            // Displaying any errors that 
            // might have occured.
            MessageBox.Show("Error opening the " +
            "connection: " + ex.Message);
        }
        finally
        {
            objOleDbConnection.Close();
        }

        MessageBox.Show("File have been created.");
    }

Hope for some tips. Regards.

Answer 1

Open connection to DB in exclusive mode , described in Working with Database Passwords in VBA Code .

OleDbConnection objOleDbConnection = new OleDbConnection(
    "Provider=Microsoft.ACE.OLEDB.12.0;" +
    "Data Source=" + sfdNewFile.FileName + ";Exclusive=1;");

this should work fine as well:

OleDbConnection objOleDbConnection = new OleDbConnection(
    "Provider=Microsoft.ACE.OLEDB.12.0;" + 
    "Data Source=" + sfdNewFile.FileName + ";Mode=12;");

Edit:

The above is for " Cannot change password on a shared open database. ".

If you still have an Cannot open the MS Office Access database engine workgroup information file error try add Jet OLEDB:System database to connection string that points to System.MDW file (locate it using "search"). It might looks like:

OleDbConnection objOleDbConnection = new OleDbConnection(
    "Provider=Microsoft.ACE.OLEDB.12.0" +
    ";Data Source=" + sfdNewFile.FileName + 
    ";Jet OLEDB:System database=C:\...\System.MDW"
    ";Exclusive=1;");

Answer 2

I don't think you can change a user name directly. Consider than a SQL UPDATE is analogous to a DELETE combined with an INSERT . Likewise, combine CREATE and DROP eg

instead of (pesudocode)

ALTER USER HelpNeeder SET uid = onedaywhen; -- no such syntax

try (actual code):

CREATE USER onedaywhen pwd H3sJaZ9k2m;
DROP USER HelpNeeder;

Then GRANT the new user the same privileges as the old ;)

ps I don't think the user name and password values can be parameterized.