MongoDB\Driver\ReadPreference::getTagSets
MongoDB\Driver\ReadConcern::__construct
MongoDB\Driver
PHP Manual

# The MongoDB\Driver\ReadConcern class

(mongodb >=1.1.0)

## Introduction

MongoDB\Driver\ReadConcern controls the level of isolation for read operations for replica sets and replica set shards. This option requires the WiredTiger storage engine and MongoDB 3.2 or later.

## Class synopsis

final MongoDB\Driver\ReadConcern {
/* Constants */
const string LOCAL = local ;
const string MAJORITY = majority ;
/* Methods */
final public __construct ([ string `$level` ] )
final public string|null getLevel ( void )
}

## Predefined Constants

`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 level.

`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).

## Table of Contents

- MongoDB\Driver\ReadConcern::__construct — Construct immutable ReadConcern
- MongoDB\Driver\ReadConcern::getLEvel — Returns the ReadConcern's "level" option

MongoDB\Driver\ReadPreference::getTagSets
MongoDB\Driver\ReadConcern::__construct
MongoDB\Driver
PHP Manual