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Stored procedures
Locks a data file and restricts the access to this data file for all other sites or applications. Then, the data file can be unlocked by <Source>.UnlockFile.
Several cases may occur after the call to <Source>.LockFile:
  • A file record is already locked by another application: the lock cannot be performed.
  • The data file is already locked by another application: the lock cannot be performed.
HErrorLock returns True if a lock problem occurs.
AndroidAndroid Widget Java This function can be used with HFSQL Client/Server data files.
Example
// Lock the CUSTOMER data file
IF Customer.LockFile(hLockReadWrite) = False THEN
IF HErrorLock() = True THEN
Error("Operation not allowed")
END
END
// Process on data file ...
...
// Restore access to data file
Customer.UnlockFile()
Syntax
<Result> = <Source>.LockFile([<Lock>])
<Result>: Boolean
  • True if the lock was performed,
  • False if a problem occurred (the file is already locked for example). HError is used to identify the error.
<Source>: Type corresponding to the specified source
Name of the data file used.
<Lock>: Optional integer constant
Used to define the type of lock performed on the data file:
hLockNoNo effect
hLockReadWriteLock in read/write: the records found in the data file cannot be read or modified by another application. No lock on the data file can be defined by another application.
hLockWrite
(default value)		Lock in write mode: the records found in the data file can be read by another application but cannot be modified by another application. No lock on the data file can be defined by another application.

Hyper File 5.5 <Lock> is ignored.
AndroidAndroid Widget Java The management of locks is performed on the HFSQL Client/Server data files only.
Remarks

Modifying the type of lock for a data file

To modify the type of lock applied to a data file, call <Source>.LockFile and specify the requested type of lock. There is no need to unlock the data file beforehand.

Effect of lock mode

If the data file lock mode is set to hModeMono (see <Source>.Mode), <Source>.LockFile has no effect.

Lock failure

If the data file (or one of its records) is already locked, the lock request is retried H.NbRetry times (50 by default).
If the data file cannot be locked after H.NbRetry attempts, HErrorLock returns True.
Component: wd280hf.dll
See also
Minimum version required
  • Version 25
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