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  • Read operation according to a key item or not
  • Memos
  • Lock
  • Miscellaneous
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Stored procedures
Moves several records forward from the current position in the data file, according to a specified item.
The destination record is read and loaded in memory: HFSQL variables are updated (e.g. Customer.Name, i.e. item Name of data file Customer).
Several cases may occur after the call to <Source>.Forward:
  • no other record exists in the data file: <Source>.Out returns True. No read operation is performed.
  • the function tries to lock a record that is already locked in read-only: HErrorLock returns True and <Source>.Out returns True.


    Android Management of locks not available in SQLite databases.
This function can be used with the HFSQL files, views or queries.
Example
// Moves to the 2000th record
// of the Customer file according to the CustName key
Customer.ReadFirst(CustName)
Customer.Forward(CustName, 1999)
HFSQL ClassicHFSQL Client/ServerNative Connectors (Native Accesses)
// Test of the <Source>.Forward status report
// Moves to the 2000th record
// of the Customer file according to the CustName key
Customer.ReadFirst(CustName)
IF Customer.Forward(CustName, 1999, hLockWrite) = False THEN
IF HErrorLock() = True THEN
Info("This record is currently used")
ELSE
Error(HErrorInfo())
END
END
Syntax
<Result> = <Source>.Forward([<Item> [, <Step> [, <Options>]]])
<Result>: Boolean
  • True if the move was performed in the file,
  • False if an error occurred (lock, end of file, etc.): the record is not read. HError is used to identify the error.
<Source>: Type corresponding to the specified source
Name of data file, view or query used.
<Item>: Optional character string
Name of item according to which the browse is performed.
If this name is not specified, <Source>.Forward handles the last item in the data file used by the last HFSQL function (function starting with "H").
<Step>: Optional integer
Number of steps forward (which means number of records to browse). By default, <Step> = 1.
<Options>: Optional Integer constant (or combination of constants)
Configures:
  • the lock mode applied to the record read. By default, the lock performed corresponds to the current lock.
    hLockNoNo lock: the record can be read or modified by another application during the reading.
    hLockReadWriteLock in read/write: the record currently read cannot be read or modified by another application.
    hLockWriteLock in write mode: the record currently read can be read by another application but it cannot be modified by another application.

    Native 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.

    AndroidAndroid Widget Management of locks not available in SQLite databases.
  • the management of duplicates during the browse. By default, all the duplicates are browsed.
    hDistinctWhen a browse is performed on a key item, a single record is browsed if duplicates are found.
Remarks

Read operation according to a key item or not

In all cases, the browse operation must have been initialized by one of the following functions: <Source>.ReadFirst, <Source>.First, <Source>.ReadSeekFirst, <Source>.SeekFirst, <Source>.ChangeKey, <Source>.RestorePosition.
If the item used is a key item:
  • if the hDistinct constant is not specified, <Source>.Forward moves forward <Step> key values from the current position.
  • if the hDistinct constant is specified, <Source>.Forward moves forward <Step> key values from the current position. If duplicates are found, a single duplicate is read.
If the item used is not a key item:
  • the hDistinct constant is not available.
  • <Source>.Forward moves foward from <Step> active records from the current position.

Memos

The memos associated with the record can be automatically read (or not) when reading the record. <Source>.SetMemo is used to customize this automatic read operation.
If the memos are supported, the associated text memos are read when the record is read. The binary memos are read only when they are explicitly used (<Source>.ExtractMemo).

Lock

By default (no lock variable specified), the lock performed corresponds to the current lock mode.
If a lock is specified (hLockWrite or hLockReadWrite constant), the record will be read and locked only if it is not already locked by another application.
Native 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.

Miscellaneous

Component: wd290hf.dll
Minimum version required
  • Version 25
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Last update: 07/06/2023

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