MongoDB\Driver\ReadConcern
PHP Manual

MongoDB\Driver\ReadConcern::__construct

Construct immutable ReadConcern

Description

final public MongoDB\Driver\ReadConcern::__construct ([ string $level ] )

Creates a new ReadConcern.

Parameters

level

Read concern
Value Description
MongoDB\Driver\ReadConcern::LOCAL Queries using this read concern will return the node's most recent copy of the data. This provides no guarantee that the data has been written to a majority of the nodes (i.e. it may be rolled back). This is the default read concern for MongoDB.
MongoDB\Driver\ReadConcern::MAJORITY Queries using this read concern will return the node's most recent copy of the data confirmed as having been written to a majority of the nodes (i.e. the data cannot be rolled back).

Errors/Exceptions

  • Throws MongoDB\Driver\Exception\InvalidArgumentException on argument parsing errors.

Examples

Example #1 MongoDB\Driver\ReadConcern::__construct example

<?php

/* Unspecified read isolation level (uses the server's default behavior) */
$rc = new MongoDB\Driver\ReadConcern();

/* Request read isolation from a single replica set node */
$rc = new MongoDB\Driver\ReadConcern(MongoDB\Driver\ReadConcern::LOCAL);

/* Request read isolation from a majority of the replica set nodes */
$rc = new MongoDB\Driver\ReadConcern(MongoDB\Driver\ReadConcern::MAJORITY);

?>