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  • Read operation based on a key
  • Comparison between HNext and HReadNext
  • Miscellaneous
  • Locks
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Stored procedures
Sets the position on the next data file record according to a browse item. The record is not read.
The number of the current record is modified only when it is returned by HRecNum. For the functions that handle the current record number (HDelete, HRead, HModify, etc.), the value of this number is not updated: you must use HRecNum(). For example: not to do:
HDelete(Customer)
but
HDelete(Customer, HRecNum())
Values in the browse item are read in ascending order (see Remarks for more 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 most cases, HNext sets the position in the data file to loop through the records that match a condition. HNext is used to position on the next record corresponding to the condition.
Several cases may occur after the call to HNext:
  • a record corresponding to the condition was found: HFound returns True
  • the data file is empty or there is no record corresponding to the condition: HOut returns True
Remarks:
  • By default, HSeekFirst and HSeekLast are used to perform an exact-match search.
  • By default, HNext performs a generic search.

Values in the browse item are read in ascending order (for more details, see the remarks).
Caution: The record loaded in memory is not modified. The HFSQL variables (for example Customer.Name, i.e. the Name item of the Customer file) are not updated.
Generally, HNext sets the position in the data file during a loop operation.
Several cases may occur after the call to HNext:
  • the data file is empty or no record corresponds 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.
    Java Access by JDBC: Locks cannot be managed in databases accessed by JDBC.
Example
HFirst(Customer, Name)
WHILE HOut(Customer) = False
// Process the record
HNext(Customer, Name)
END
Syntax
<Result> = HNext([<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, etc.): 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 HFSQL data file. If this parameter is an empty string (""), HNext manipulates the last data file used by the last HFSQL function (function starting with "H").
<Search key item>: Optional character string
Name of the key item used to loop through the data file. If this name is not specified, HNext will use the last browse item used on this data file by the last HFSQL management function (function starting with "H"). If this item does not exist, the best browse item is automatically used.
<Options>: Optional constant
Configures the lock and the management of duplicates performed on the record selected by HNext:
hDistinctIf there are any duplicates, sets the position on a single record of the duplicates. This parameter is taken into account only if the iteration is performed on a key item.
By default, all duplicates are iterated over.
OLE DBNative Connectors (Native Accesses) This constant is ignored.
hLockNoNo lock: the record can be read or modified by another application.
hLockReadWriteLock in read/write: the selected record cannot be read or modified by another application.
OLE DB Lock in write-only: the record currently read can be read by another application but it cannot be modified.
Operating mode equivalent to the one of hLockWrite.
hLockWriteLock in write mode: the selected record can be read by another application but it cannot be modified.
Java Access by JDBC: This parameter is ignored.
OLE DBNative Connectors (Native Accesses) The lock options will have no effect if the locks are not supported by the OLE DB provider or by the Native Connector.
OLE DB The lock mode specified with HReadNext will remain effective when HReadFirst and HReadPrevious are called.
To change the lock mode, use:
Hyper File 5.5 The lock options are ignored. Use the lock functions (HLockRecNum) kept for backward compatibility.
Remarks

Read operation based on a key

HNext positions on the next record with the greatest key value. The sort order taken into account is the one specified in the analysis for this key.

Comparison between HNext and HReadNext

HNext does not read the record: therefore, HNext is faster than HReadNext.

Miscellaneous

  • HRecNum returns the current record number.
  • HChangeKey changes the search key while keeping the position on the current record.
WINDEVWEBDEV - Server codeReports and QueriesUniversal Windows 10 AppiPhone/iPadJavaUser code (UMC)External languageAjaxHFSQLHFSQL Client/ServerHyper File 5.5OLE DBNative Connectors (Native Accesses)

Locks

By default (<Options> not specified), the record is not locked.
If a lock is requested (hLockWrite or hLockReadWrite constant), the position will be set on the record only if it is not already locked.
Component: wd280hf.dll
Minimum version required
  • Version 9
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