PRB: Must Open MDB on Read-Only Media with adShareDenyWrite

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Article ID: 195475 - View products that this article applies to.
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Opening the connection on a read-only Microsoft Access Database (.mdb file on a CD-ROM, a floppy disk that is write protected, or a hard disk that is read-only to the user, and so forth) with the following code causes an error to occur. The following code opens a connection on a Microsoft Access database file on a CD-ROM:
   Dim con as new ADODB.Connection
   con.Provider = "Microsoft.Jet.Oledb.3.51"
   con.Open "Data Source=E:\testdb.mdb"
It causes the following error:
The Microsoft Jet database engine cannot open the file E:\testdb.mdb. It is already opened exclusively by another user, or you need permission to view its data.


The Jet OLEDB provider opens databases, by default, in Read/Write mode. Jet requires the creation of a locking file (.ldb file) in order to open a database file in shared access mode. If you request shared access mode, Jet attempts to create the locking file, which fails on read-only media. If you open a database using exclusive mode, Jet does not need to create the locking file.


Open the database in read-only and exclusive mode. You can do this by setting the Mode property of the connection object to adShareDenyWrite.

The following code opens a connection on a read-only Microsoft Access database:
   Dim con as new ADODB.Connection
   con.Provider = "Microsoft.Jet.Oledb.3.51"
   con.Mode = adShareDenyWrite
   con.Open "Data Source=E:\testdb.mdb"


The following Microsoft Knowledge Base article describes the same problem and a resolution when using Data Access Object (DAO):
191737 PRB: DAO MDB on Read-Only Media Must Be Opened Exclusively
Microsoft Developer Network Library, Visual Studio 6.0; search on:
Microsoft Data Access SDK


Article ID: 195475 - Last Review: October 15, 2003 - Revision: 2.0
  • Microsoft OLE DB Provider for Jet 3.51, when used with:
    • Microsoft Data Access Components 2.0
kbdatabase kbjet kbprb KB195475
Retired KB Content Disclaimer
This article was written about products for which Microsoft no longer offers support. Therefore, this article is offered "as is" and will no longer be updated.

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