(mongodb >=1.0.0)
MongoDB\Driver\WriteResult::getModifiedCount — Returns the number of existing documents updated
If the update operation results in no change to the document (e.g. setting the value of a field to its current value), the modified count may be less than the value returned by MongoDB\Driver\WriteResult::getMatchedCount().
此函数没有参数。
Returns the number of existing documents updated, or NULL if the write was
not acknowledged.
The modified count is not available on versions of MongoDB before 2.6, which
used the legacy wire protocol version (i.e. OP_UPDATE). If this is the case,
the modified count will also be NULL.
Example #1 MongoDB\Driver\WriteResult::getModifiedCount() example
<?php
$manager = new MongoDB\Driver\Manager;
$bulk = new MongoDB\Driver\BulkWrite;
$bulk->insert(['x' => 1]);
$bulk->update(['x' => 1], ['$set' => ['y' => 3]]);
$bulk->update(['x' => 2], ['$set' => ['y' => 1]], ['upsert' => true]);
$bulk->update(['x' => 3], ['$set' => ['y' => 2]], ['upsert' => true]);
$bulk->delete(['x' => 1]);
$result = $manager->executeBulkWrite('db.collection', $bulk);
var_dump($result->getModifiedCount());
?>
以上例程会输出：
int(1)