MongoDB\Driver\Cursor::isDead
Checks if the cursor is exhausted or may have additional results
説明
final public bool MongoDB\Driver\Cursor::isDead()
A cursor has no additional results and is considered "dead" when one of the
following is true:
-
The current batch has been fully iterated and the
cursor ID is zero (i.e. a
» getMore
cannot be issued).
- An error was encountered while iterating the cursor.
- The cursor reached its configured limit.
By design, it is not possible to always determine whether a cursor has
additional results. The cases where a cursor may have
more data available is as follows:
-
There are additional documents in the current batch, which are buffered on
the client side. Iterating will fetch a document from the local buffer.
-
There are no additional documents in the current batch (i.e. local buffer),
but the cursor ID is non-zero. Iterating will request more documents from
the server via a
» getMore
operation, which may or may not return additional results and/or indicate
that the cursor has been closed on the server by returning zero for its ID.
戻り値
Returns true if there are definitely no additional results available on the
cursor, and false otherwise.
エラー / 例外
- Throws MongoDB\Driver\Exception\InvalidArgumentException on argument parsing errors.
例
例1 MongoDB\Driver\Cursor::isDead example
<?php
$manager = new MongoDB\Driver\Manager("mongodb://localhost:27017");
$query = new MongoDB\Driver\Query([]);
$bulk = new MongoDB\Driver\BulkWrite;
$bulk->insert(['x' => 1]);
$bulk->insert(['x' => 2]);
$bulk->insert(['x' => 3]);
$manager->executeBulkWrite('db.collection', $bulk);
$cursor = $manager->executeQuery('db.collection', $query);
$iterator = new IteratorIterator($cursor);
$iterator->rewind();
var_dump($cursor->isDead());
$iterator->next();
var_dump($cursor->isDead());
$iterator->next();
var_dump($cursor->isDead());
$iterator->next();
var_dump($cursor->isDead());
?>
bool(false)
bool(false)
bool(false)
bool(true)