CollectionFind::lockExclusive

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CollectionFind::lockExclusive — Execute operation with EXCLUSIVE LOCK

说明

public mysql_xdevapi\CollectionFind::lockExclusive(int $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.

参数

lock_waiting_option

Optional waiting option. By default it is MYSQLX_LOCK_DEFAULT. Valid values are these constants:

返回值

Returns a CollectionFind object that can be used for further processing.

示例

示例 #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();
?>