ONLINE HELP
 WINDEVWEBDEV AND WINDEV MOBILE

Help / WLanguage / Managing databases / HFSQL / HFSQL functions
  • Handling a crossed record
  • Number of crossed records
  • Version of data file
  • Crossing a record from a query
  • Special cases
  • xBase files
WINDEV
WindowsLinuxUniversal Windows 10 AppJavaReports and QueriesUser code (UMC)
WEBDEV
WindowsLinuxPHPWEBDEV - Browser code
WINDEV Mobile
AndroidAndroid Widget iPhone/iPadIOS WidgetApple WatchMac CatalystUniversal Windows 10 App
Others
Stored procedures
Crosses a record in a data file. The record is deleted logically and it can be retrieved if necessary.
The following operations are performed:
  • the record becomes inactive. The data is stored (which is not the case when a record is deleted by HDelete).
  • the indexes (corresponding to the record keys) are deleted from the index file.
  • the memos associated with the record are stored.
This function can be used on the data files, the HFSQL Mobile views or the queries.
Example
// Crosses the record #123
HCross(Customer, 123)
// Cross the customer orders
HReadSeekFirst(ORDERS, CUSTNUM, ValCustNum)
WHILE HFound() = True
HCross()
HReadNext()
END
Syntax
<Result> = HCross([<Data file> [, <Record number> [, <Options>]]])
<Result>: Boolean
  • True if the record was crossed,
  • False if an error occurred (locked record, integrity error, ...). HErrorInfo returns more details.
<Data file>: Optional character string
Name of HFSQL data file, query or view used.
If this parameter is an empty string (""), HCross manipulates the last data file used by the last HFSQL function (function starting with "H").
<Record number>: Optional integer
Number of the record to cross.
If this parameter is not specified (equal to 0 or to the hCurrentRecNum constant), the current record will be crossed.
<Options>: Optional constant
Configures:
  • the lock mode applied to the crossed record. If no lock constant is specified, the crossed record is not locked.
    hLockNo
    (default value)
    No lock: the crossed record will not be locked.
    hLockReadWriteLock in read/write: the current crossed record cannot be read or re-enabled by another application.
    hLockWriteLock in write mode: another application can read and consult the current crossed record (HRead) but cannot re-enable it. Only the current application can re-enable it.
  • the integrity management applied to the crossed record.
    hCheckIntegrityChecks the integrity for the operation, even if the automatic integrity check is disabled (HSetIntegrity).
    hIgnoreIntegrityIgnores the integrity check for this operation, even if the automatic integrity check is enabled (HSetIntegrity).

    A WLanguage error occurs if the two constants are used at the same time. These constants have no effect on the cascading deletion.
Remarks

Handling a crossed record

Number of crossed records

HNbRec is used to find out the number of crossed records in the data file.
Remark: For backward compatibility with WEBDEV 1.5/WINDEV 5.5, the number of crossed records can also be returned by the H.NbDel variable.

Version of data file

If HCross is successful, the data file version number is modified. This version number is returned by HVersion.

Crossing a record from a query

A record can be crossed:
  • in the query result.
  • in the files handled by the query (hModifyFile constant used in HExecuteQuery or HExecuteSQLQuery). In this case, the hWithFilter constant is automatically selected.
Regardless of the query execution mode (with or without the hWithFilter constant), HCross can only be used on single-file queries.
Caution:
  • Records cannot be crossed in a query that uses groups or aggregates.
  • The management of integrity and duplicates is not performed during the operations on the multi-file queries: it is recommended to use transactions to avoid any problems.

Special cases

  • Managing locks:
    If a lock problem occurs when "crossing" a record (attempt to cross a record locked in write mode for example), the record is not modified and HErrorLock returns True.
  • Managing the referential integrity
    If the management of the referential integrity is enabled (HSetIntegrity) and if the integrity is not checked during the deletion, HCross is not run. HErrorIntegrity must be checked after HCross.
  • Deleted records
    HCross must not be called on a record that was deleted beforehand.
WINDEVNative Connectors (Native Accesses)

xBase files

HDelete and HCross have the same effect: the record is crossed but it is not deleted. Therefore, the record can be re-enabled using HModify. In this case, HState returns the hStateCrossed constant for a deleted record (instead of hStateDel).
Component: wd290hf.dll
Minimum version required
  • Version 9
This page is also available for…
Comments
Click [Add] to post a comment

Last update: 05/26/2022

Send a report | Local help