VB Application Incorrectly Indicates Lost Data Record (120515)
The information in this article applies to:
- Microsoft Windows NT Server 3.1
- Microsoft Windows NT Workstation 3.1
This article was previously published under Q120515 SYMPTOMS
When Visual Basic applications do not include proper error handling when
performing database record processing, the applications may report null
records and the following error message appears:
Error #70: ....File Locked.
In this case, Windows for Workgroups workstations that are reading records
to a database stored on a Windows NT Advanced Server system may
incorrectly report lost records. Record write failures may also lose
records in a similar way.
CAUSE
Although the server reports a locking violation to the workstation, the
application does not handle the error. Null record values are returned
during a read failure. Data being written may appear to be lost if the
write fails to complete. Protocol analysis will show that the Windows NT
Advanced Server system returns a server message block (SMB) locking
violation.
RESOLUTION
If the application receives a locking violation, the application must
handle this error by backing off and waiting for a period of time. This
period of time must be determined to be reasonable based on a normal
period that a user will require exclusive access to a data record. After
waiting, the application can then attempt to retry the operation. The
application backs off and retries the operation until it is successful, or
it returns an appropriate error message to the user indicating that the
record is not accessible at this time. Proper error handling is critical
to guaranteeing successful data record reading and writing.
| Modification Type: | Major | Last Reviewed: | 11/4/2003 |
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| Keywords: | KB120515 |
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