MongoDB\Driver\WriteConcern::isDefault
(mongodb >=1.3.0)
MongoDB\Driver\WriteConcern::isDefault — Checks if this is the default write concern
説明
Returns whether this is the default write concern (i.e. no options are specified). This method is primarily intended to be used in conjunction with MongoDB\Driver\Manager::getWriteConcern() to determine whether the Manager has been constructed without any write concern options.
The driver will not include a default write concern in its write operations (e.g. MongoDB\Driver\Manager::executeBulkWrite()) in order to allow the server to apply its own default, which may have been » modified. Libraries that access the Manager's write concern to include it in their own write commands should use this method to ensure that default write concerns are left unset.
パラメータ
この関数にはパラメータはありません。
返り値
Returns TRUE if this is the default write concern and FALSE otherwise.
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\WriteConcern::isDefault() example
<?php
$wc = new MongoDB\Driver\WriteConcern(1);
var_dump($wc->isDefault());
$manager = new MongoDB\Driver\Manager('mongodb://127.0.0.1/?w=majority');
$wc = $manager->getWriteConcern();
var_dump($wc->isDefault());
$manager = new MongoDB\Driver\Manager('mongodb://127.0.0.1/');
$wc = $manager->getWriteConcern();
var_dump($wc->isDefault());
?>
上の例の出力は以下となります。
bool(false) bool(false) bool(true)
参考
- MongoDB\Driver\Manager::getWriteConcern() - Return the WriteConcern for the Manager
- » Modify Default Write Concern in the MongoDB manual
- » Write Concern reference
忘却曲線を使ってこの知識を確実に記憶に残す
