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  • Error cases
  • Handling records during a transaction
  • Transactions and independent HFSQL context
  • OLE DB and Native Connectors
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Stored procedures
Validates the current transaction:
  • the modifications performed on the data file since the start of transaction (HTransactionStart or HTransaction) are validated.
  • the transaction file is deleted (if this transaction is the last transaction in progress for a network application).
  • the records locked in read-only by the transaction are unlocked.
AndroidAndroid Widget iPhone/iPadIOS WidgetMac Catalyst The management of transactions is available for HFSQL Client/Server databases.
Example
MyConnection1 is Connection
 
// Start transaction on data files associated with MyConnection1
HTransactionStart(MyConnection1)
 
// Code used to prepare the order to added
// ...
 
WHEN EXCEPTION IN
// Add the order
HAdd(Orders)
// Validate the addition
HTransactionEnd(MyConnection1)
DO
// Delete the order lines
HTransactionCancel(MyConnection1)
END
// Start transaction on the Orders and OrdLine data files
HTransactionStart("C:\Temp\Transaction.trs", "Orders,OrdLine,-Customer")
 
// Code used to prepare the order to added
// ...
 
WHEN EXCEPTION IN
// Add the order
HAdd(Orders)
// Validate the addition
HTransactionEnd()
DO
// Delete the order lines
HTransactionCancel()
END
Syntax

Validating a transaction in progress on a connection Hide the details

<Result> = HTransactionEnd(<Connection>)
<Result>: Boolean
  • True if the transaction is ended,
  • False if a problem occurs. HErrorInfo returns more details about the error.
Caution: The function has no effect if a global transaction is started. The syntax 2 must be used.
<Connection>: Character string or Connection variable
Connection to use. This connection corresponds to: If this parameter corresponds to the hAccessHF7 constant, the transaction will be performed on HFSQL ISAM files.

Validating a global transaction in progress Hide the details

<Result> = HTransactionEnd()
<Result>: Boolean
  • True if the transaction is ended,
  • False if a problem occurs. HErrorInfo returns more details about the error.
Remarks

Error cases

  • Nesting transactions: Transactions cannot be nested (i.e. HTransactionStart or HTransaction cannot be called in a transaction). In this case, error 70031 occurs.
  • A fatal error is displayed in the following cases:
    • A transaction is started on all the connections while there is at least one connection in transaction.
    • A transaction is started on a connection while a transaction was already started on all the connections.
    • A transaction is started on all the connections while there is at least one connection whose isolation mode is not "Read Uncommitted".

Handling records during a transaction

During a transaction, some rules must be complied with when handling the records. For more details, see Transactions: Handling records during a transaction.

Transactions and independent HFSQL context

When copying a context, if a transaction is in progress on the first context, the new context is not in transaction. You must call HTransactionStart (or HTransaction) to start a transaction in the new context.
WINDEVWEBDEV - Server codeOLE DBNative Connectors (Native Accesses)

OLE DB and Native Connectors

Only syntaxes with connection are taken into account by the Native Connectors (also called Native Accesses) that support transactions. You can also use SQLTransaction.
Component: wd270hf.dll
Minimum version required
  • Version 9
This page is also available for…
Comments
Example in doc correcton
When using Transaction commands Start, End and Cancel always include the connection or source used in the Start in the associated End and Cancel

TransactionStart(MyConnection)

Hadd(Customer)
if ErrorOccurred() then
TransactionCancel(MyConnection)
ELSE
TransactionEnd(MyConnection)
END
CCordes
03 Oct. 2019
Example Transaction with commit 100 in 100
//SQL

SERIAL is int

HTransactionStart(Hfsql)

FOR EACH t0010_enderecoscorreios //leitura da tabela ms sql server // TABELA DE ORIGEM

SERIAL += 1

PROGBAR_01..Value += 1
IF PROGBAR_01..Value = 100 THEN
HTransactionEnd(Hfsql) //commit
PROGBAR_01..Value = 0
HTransactionStart(Hfsql) //start
Multitask(1) //permite compartilhar o processador com os outros prog e serviços windows
END

//HFSQL = MS SQL SERVER 2016 / DEVELOPER
enderecoscorreios.LogradouroAbrev = t0010_enderecoscorreios.LogradouroAbrev
enderecoscorreios.Logradouro = t0010_enderecoscorreios.Logradouro

ok is boolean = HAdd(enderecoscorreios) // gravacao no hfsql
IF ok = False THEN
HTransactionCancel(Hfsql) //Rollback
END

END

Info(SERIAL)
BOLLER
13 Apr. 2017