Create a new ReadConcern

# MongoDB\Driver\ReadConcern::__construct

(mongodb >=1.0.0)

MongoDB\Driver\ReadConcern::__construct — Create a new ReadConcern

### 説明

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

Constructs a new MongoDB\Driver\ReadConcern, which is an immutable value object.

### パラメータ

`level`

  The » read concern level. You may use, but are not limited to, one of the class constants.

### エラー / 例外

- 引数のパースに失敗した場合に MongoDB\Driver\Exception\InvalidArgumentException をスローします。

### 例

例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);
?>`

### 参考

- » Read Concern reference