How to Recover Corrupt DataBase Container Files

 Last reviewed: April 30, 1996
Article ID: Q129168
The information in this article applies to:
  • Microsoft Visual FoxPro for Windows, version 3.0

SUMMARY

The best way to ensure that you will be able to recover corrupt DBC files is to use proactive measures, such as frequently backing up the Database files (both the .DBC and .DCT files). The next best method is to use the GENDBC.PRG tool located in the VFP\TOOLS\GENDBC subdirectory.

GENDBC.PRG is a utility that generates a custom .PRG file that can then be executed to re-build the DataBase Container that GENDBC was run against. The resulting .PRG file, when run, will recreate the DataBase Container to the state prior to when GENDBC was run against it. Thus it may be necessary to run GENDBC many times during the development life cycle to prevent loss of work if the files are damaged.

MORE INFORMATION

When GENDBC.PRG is run, it creates a "generation" program file for the current Database container. If no Database is open it will prompt for one.

To use GENDBC, execute it from the Command window. For example: 

   DO C:\VFP\TOOLS\GENDBC\GENDBC.PRG WITH 'GD_MYDBC'
When GENDBC.PRG is finished, a program file with the same name as the database will be created in the current directory. This program can then be executed to recreate damaged Database (.DBC) files. For instance, in the example above, a program named "GD_MYDBC.PRG" would be created.

If the Database (.DBC) file is corrupt or damaged at the table level (in other words, the .DBC is a FoxPro Table (.DBF)) and it is not usable as a FoxPro table, GENDBC will not correct the matter. The error generated in this case is: 

   UNRECOVERABLE ERROR...FILE <path>\dbc_name.dbc IS NOT A
   DATABASE AT LINE <line_no>
If this is the case, a third-party database repair utility will be required to repair the DBC at the table level. However, once the file is corrected in this manner, there is still no guarantee that the .DBC file will be recoverable with GENDBC.PRG. Thus the importance of using GENDBC.PRG prior to using the Database or immediately following any changes to the Database Container.

For additional information on repairing a corrupt database, please see the following article in the Microsoft Knowledge Base:

ARTICLE-ID: Q129400 TITLE: Free Table Command Removes Table From Corrupted Database

Additional reference words: 3.00 VFoxWin remove free damage
corrupted
KBCategory: kbprg kbtshoot
KBSubcategory: FxprgTable

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Last reviewed: April 30, 1996
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