CollectionFind::lockExclusive
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CollectionFind::lockExclusive — Execute operation with EXCLUSIVE LOCK
Descrizione
$lock_waiting_option = ?): mysql_xdevapi\CollectionFind
Locks the document exclusively.
As long as the document is locked,
other transactions can't update the document,
use SELECT ... LOCK IN SHARE MODE,
or read the data in certain transaction isolation levels.
Consistent reads ignore any locks set on the records that exist in the read view.
To avoid concurrency problems, it makes sense to use this function with the mysql_xdevapi\Collection::modify() method. Essentially, this function uses row locks to serialise access to rows.
Elenco dei parametri
-
lock_waiting_option -
Optional waiting option. By default it is
MYSQLX_LOCK_DEFAULT. Valid values are these constants:MYSQLX_LOCK_DEFAULTMYSQLX_LOCK_NOWAITMYSQLX_LOCK_SKIP_LOCKED
Valori restituiti
Returns a CollectionFind object that can be used for further processing.
Esempi
Example #1 mysql_xdevapi\CollectionFind::lockExclusive() example
<?php
$session = mysql_xdevapi\getSession("mysqlx://user:password@localhost");
$schema = $session->getSchema("addressbook");
$collection = $schema->createCollection("people");
$session->startTransaction();
$result = $collection
->find("age > 50")
->lockExclusive()
->execute();
// ... do an operation on the object
// Complete the transaction and unlock the document
$session->commit();
?>
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