MongoDB\Driver\Manager::getReadPreference

(mongodb >=1.0.0)

MongoDB\Driver\Manager::getReadPreference — Return the ReadPreference for the Manager

说明

final public MongoDB\Driver\Manager::getReadPreference ( void ) : MongoDB\Driver\ReadPreference

Returns the MongoDB\Driver\ReadPreference for the Manager, which is derived from its URI options. This is the default read preference for queries and commands executed on the Manager.

参数

此函数没有参数。

返回值

The MongoDB\Driver\ReadPreference for the Manager.

错误／异常

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

范例

Example #1 MongoDB\Driver\Manager::getReadPreference() example

 <?php

$manager = new MongoDB\Driver\Manager('mongodb://localhost:27017');
var_dump($manager->getReadPreference());

$manager = new MongoDB\Driver\Manager('mongodb://localhost:27017/?readPreference=secondaryPreferred&readPreferenceTags=dc:ny,rack:1&readPreferenceTags=dc:ny&readPreferenceTags=');
var_dump($manager->getReadPreference());

?>

以上例程的输出类似于：

object(MongoDB\Driver\ReadPreference)#2 (1) {
  ["mode"]=>
  string(7) "primary"
}
object(MongoDB\Driver\ReadPreference)#1 (2) {
  ["mode"]=>
  string(18) "secondaryPreferred"
  ["tags"]=>
  array(3) {
    [0]=>
    object(stdClass)#3 (2) {
      ["dc"]=>
      string(2) "ny"
      ["rack"]=>
      string(1) "1"
    }
    [1]=>
    object(stdClass)#4 (1) {
      ["dc"]=>
      string(2) "ny"
    }
    [2]=>
    object(stdClass)#5 (0) {
    }
  }
}

参见

MongoDB\Driver\ReadPreference
MongoDB\Driver\Manager::__construct() - Create new MongoDB Manager