Base cannot connect to driver class

Libreoffice Base crashed after I tried running an sql query. Ever since then, although the file will open but all my tables and forms are gone. If I try to start a table or a form I get an error message saying that it cannon connect to the driver class. Error details: SQL state: HY000, Error code 1000. A locked file with the same name as my database and the extension .lck (name.odb.lck) remains in my database folder even when the file is closed. Any way I can reconnect to or retrieve my data?
Libreoffice 4.3.4.1
Windows 7

Sounds like your file has been corrupted.
The lck file only contains part of the data in your database. Even assuming that you could rename this to just odb by removing the lck extension in the file manager, it is doubtful whether you could actually retrieve anything of use. The best way to check would be to :

  1. Shut down LO completely, including any quickstarter process
  2. Remove the lck extension.
  3. Change the ODB extension to zip
  4. Un zip the file and inspect the contents, preferably in a text editor. If some things appear salvageable (e.g. filesize indicates that most of the data is still there), you can then try and create an empty ODB file in LO. Close LO and rename the new ODB file to a zip extension. Unzip it and then copy over the data, forms, etc from your previous lck file to the new ODB/ZIp file, then rezip and rename to ODB, and attempt to reopen in LO.