- Update Center for Microsoft SQL Server
- Font and Icons too small when RDP from Windows 10 into Windows 7
- One problem, one weekend, eight languages
- How to retrive Outlook default signature
- How to completely uninstall VFP 9.0
- Retrieving VFP runtime DLL name required by EXE or DLL
- Send email via MSN email account
- Send email via Yahoo mail account
- Remove Structural CDX or Memo flag from a table
- Deleting pages from PDF file through Acrobat automation
Remove Structural CDX or Memo flag from a table
The VFP low level file functions (LLFF) can be used to open a table as a file and read/write its header. The Table Header Record Structure is documented in VFP help under Table File Structure.
Note 1 Removing Structural CDX flag will effectively disassociate CDX file from the table but not delete the CDX file.
Note 2 Removing Memo flag will allow to open a table and access all fields excluding memo fields. Attempt to access the memo fields will generate an error.
| This is sample code. Add error handling and adjust to your requirements as necessary. |
* Test code CREATE TABLE temp (pk i, cc C(20), mm M) INDEX on pk TAG pk lcTableFileName = DBF() USE * Remove both *? RemoveCdxMemoFlag(lcTableFileName, "CDX MEMO") * Remove CDX flag ? RemoveCdxMemoFlag(lcTableFileName, "CDX") * Remove Memo flag ? RemoveCdxMemoFlag(lcTableFileName, "MEMO")
FUNCTION RemoveCdxMemoFlag LPARAMETERS tcTableFileName, tcFlagToRemove * tcTableFileName - Full file name including extension * tcFlagToRemove - CDX or/and MEMO LOCAL lcBuffer, llRemoveCdx, llRemoveMemo, lnCdxFlag, lnMemoFlag, lnByte28, lnFlags2remove IF VARTYPE(tcTableFileName) <> "C" OR VARTYPE(tcFlagToRemove) <> "C" * Invalid parameter(s) ERROR 11 ENDIF IF NOT FILE(tcTableFileName) * File does not exist ERROR 1, tcTableFileName ENDIF llRemoveCdx = "CDX" $ UPPER(tcFlagToRemove) llRemoveMemo = "MEMO" $ UPPER(tcFlagToRemove) IF NOT llRemoveCdx AND NOT llRemoveMemo * Invalid 2nd parameter ERROR 11 ENDIF lnCdxFlag = 0x01 lnMemoFlag = 0x02 * Open table low-level as a text file lnFh1 = FOPEN(tcTableFileName,2) IF lnFh1 < 0 ERROR 101, tcTableFileName ENDIF * Make sure that's FoxPro table lcBuffer = FREAD(lnFh1, 1) IF NOT INLIST(ASC(lcBuffer), 0x03, 0x83, 0xF5, 0x30, 0x31, 0x32) * Not a FoxPro table = FCLOSE(lnFh1) ERROR 15, tcTableFileName ENDIF * Flags at offset 28: CDX-0x01, Memo-0x02 = FSEEK(lnFh1, 28, 0) lcBuffer = FREAD(lnFh1,1) lnFlags2remove = 0 lnByte28 = ASC(lcBuffer) * Remove CDX flag if it's set IF llRemoveCdx AND BITAND(lnByte28, lnCdxFlag) <> 0 lnFlags2remove = lnFlags2remove + lnCdxFlag ENDIF * Remove Memo flag if it's set IF llRemoveMemo AND BITAND(lnByte28, lnMemoFlag) <> 0 lnFlags2remove = lnFlags2remove + lnMemoFlag ENDIF IF lnFlags2remove <> 0 * Remove cdx and/or memo flag lcBuffer = CHR(BITAND(lnByte28, 0xFF - lnFlags2remove)) * Write new byte 28 value back = FSEEK(lnFh1, 28, 0) = FWRITE(lnFh1, lcBuffer) ENDIF = FCLOSE(lnFh1) * Return combination of the flags that have been removed 0x01, 0x02 or 0x03 RETURN lnFlags2remove ENDFUNC
Comments
Rescuing Memo content
As a sidenote or additional info:
If you need to remove the memo-flag due to a corrupt memofield, you may first try my memo-rescue tool which can be found at http://code.msdn.microsoft.com/FoxPro. It copies the corrupt table and tries to read each memofield of each record. That way you loose only the corrupt ones. It also creates a log of those records with bad data.
memo-rescue tool
Hello wOOdy,
Many times your posts have helped me over a great many years!! Thanks.
BUT the code.msdn.microsoft.com link to the memo-rescue tool appears to have been eleminated!
Is there another place to get it??
thanks, Clyde
Remove Structural CDX or Memo flag from a table
This code worked perfectly. I have DBF files that are copied into an archive folder . The corresponding CDX files are not being copied. Periodically a secondary program runs to open and use the data in the DBF files. An error ( CDX not found ) would occur when the DBF was used or records selected by the program. The above code allowed the program to test each DBF as it was called and remove the CDX flag as needed. The secondary program now runs without error.
Thanks very much
An old post. but still
An old post. but still replying.
You can just use SET SAFETY OFF and USE the table. it will automatically remove the INDEX link if its not available.
Add new comment