//
// General database functions common for all modules.
//
-//-------------------------------------------------------------------
+//-------------------------------------------------------------------
+// Multilevel transaction control.
+//
+
function begin_transaction()
{
- db_query("BEGIN", "could not start a transaction");
+ global $transaction_level; // set in set_global_connection()
+
+ if (!$transaction_level) {
+ db_query("BEGIN", "could not start a transaction");
+ }
+ $transaction_level++;
}
function commit_transaction()
{
- db_query("COMMIT", "could not commit a transaction");
+ global $transaction_level;
+
+ $transaction_level--;
+
+ if (!$transaction_level) {
+ db_query("COMMIT", "could not commit a transaction");
+ }
}
+/*
+ This function is called on end of script execution to cancel
+ all aborted transactions (if any)
+*/
function cancel_transaction()
{
- db_query("ROLLBACK", "could not cancel a transaction");
+ global $transaction_level;
+
+ if ($transaction_level) {
+ db_query("ROLLBACK", "could not cancel a transaction");
+ }
}
+
//-----------------------------------------------------------------------------
// Update record activity status.
//