Sets the position on the last record of a data file according to a browse item.
The record is not read.
The number of the current Record is changed only when it is returned by the
HRecNum function. For the functions handling by default the number of the current Record (functions
HDelete,
HRead,
HModify, ...), the value of this number is not updated: you must use
HRecNum(). For example: not to do:
but
HDelete(Client, HRecNum())
get is from the smallest to the largest value of the path heading (see notes for details).
Caution: The record loaded in memory is not modified. The HFSQL variables (Customer.Name for example, which means the Name item of Customer file) are not updated.
In general, the
HLast function is used to position oneself in the data file to perform a loop among the records corresponding to a condition.
HNext is used to position on the next record corresponding to the condition.
Several cases may occur after the call to HLast:
- a record corresponding to the condition was found: function HFound returns True
- the data file is empty or there is no record corresponding to the condition: function HOut returns True
Remarks:
- By default, HSeekFirst and HSeekLast are used to perform an exact-match search.
- By Default, the function HLast performs a generic search.
Versions 15 and later
New in version 15Versions 17 and later New in version 17 Versions 18 and later New in version 18 Remark: From version 19, HFSQL is the new name of HyperFileSQL. Versions 21 and later New in version 21 The get is performed for the highest value of the route wage type (see
remarks for details).
Caution: The record loaded in memory is not modified. HFSQL variables (e. g. Customer.Name, or the Name item of the Customer data file) are not updated.
In general, the
HLast function allows you to position yourself in the data file to loop get with the
HPrevious function.
Several cases may occur after the call to HLast:
- the data file is empty or there is no record corresponding to the filter (defined by HFilter): HOut returns True.
- the function tries to lock a record that is already locked in read-only: HErrorLock returns True and HOut returns True.
Access by JDBC: The management of locks is not available for databases accessed by JDBC.
Management of locks not available in SQLite databases.
Versions 15 and later New in version 15 Versions 17 and later New in version 17 Versions 18 and later New in version 18 Versions 21 and later New in version 21 Remark: From version 19, HFSQL is the new name of HyperFileSQL.
// Parcours d'un fichier de données depuis le dernier enregistrement
HLast(Client, Nom)
WHILE NOT HOut()
// Traitement de l'enregistrement
HPrevious(Client, Nom)
END
Syntax
<Result> = HLast([<Data file>] [, <Search key item> [, <Options>]])
<Result>: Boolean
- True if the position was set,
- False if an error occurred. This problem can be caused by:
- a positioning problem (empty data file, ...): HFound returns False and HError returns 0.
- an error: HError returns an integer other than 0. HErrorInfo returns more details.
<Data file>: Optional character string
Name of the data file used. If this parameter is an empty string (""), HLast manipulates the last data file used by the last HFSQL function (function starting with "H").
<Search key item>: Optional character string
Name of key item used to browse the data file. If this name is not specified, the HLast function will handle the last path field used on this data file by the last HFSQL management function (function starting with the letter H). If this item does not exist, the best browse item is automatically used.
<Options>: Optional constant
Configures the lock set on the record selected by HLast: | |
| hLockWrite | Lock in write mode: the selected record can be read by another application but it cannot be modified by another application.
|
| hKeepFilter | The path will take into account the filter set up with the HFilter function, even if the path key used is not optimized for the filter. Reminder: function HFilter returns the optimized path key for the filter.
Caution: in this case, performance issues may arise for large files.
|
| hLockReadWrite | Lock in read/write: the selected record cannot be read or modified by another application. |
| hLockNo | No lock: the record can be read or modified by another application. |
| hNoRefresh | |
Remarks
Read operation according to a key
HLast sets the position on the record with the greatest key value.
The sort order is the one that was specified in the analysis for this key.
If duplicates are found, HLast sets the position on the first "duplicate" record according to the sequence of record numbers.
Miscellaneous
- The current record number is returned by HRecNum.
- The HChangeKey function allows you to change the route key, while remaining positioned on the current Record.
Comparing HReadLast and HLast
HLast does not read the record: therefore,
HLast is faster than
HReadLast.