(PECL mongo >=0.9.0)
MongoCollection::remove — Remove records from this collection
$criteria = array()
[, array $options = array()
]] )
criteria
Description of records to remove.
options
Options for remove.
"justOne"
Remove at most one record matching this criteria.
"safe"
Can be a boolean or integer, defaults to FALSE. If FALSE, the
program continues executing without waiting for a database response.
If TRUE, the program will wait for the database response and throw a
MongoCursorException if the update did not
succeed.
If you are using replication and the master has changed, using "safe" will make the driver disconnect from the master, throw and exception, and attempt to find a new master on the next operation (your application must decide whether or not to retry the operation on the new master).
If you do not use "safe" with a replica set and the master changes, there will be no way for the driver to know about the change so it will continuously and silently fail to write.
If safe is an integer, will replicate the update to that many machines before returning success (or throw an exception if the replication times out, see wtimeout). This overrides the w variable set on the collection.
"fsync"
Boolean, defaults to FALSE. Forces the update to be synced to
disk before returning success. If TRUE, a safe update is implied
and will override setting safe to FALSE.
"timeout"
Integer, defaults to MongoCursor::$timeout. If "safe" is set, this sets how long (in milliseconds) for the client to wait for a database response. If the database does not respond within the timeout period, a MongoCursorTimeoutException will be thrown.
If safe was set, returns an array containing the
status of the remove. Otherwise, returns a boolean representing if the
array was not empty (an empty array will not be inserted). The fields in
this array are decribed in the documentation for
MongoCollection::insert().
Throws MongoCursorException if the "safe" option is set and the remove fails.
Throws MongoCursorTimeoutException if the "safe" option is set and the operation takes longer than MongoCursor::$timeout milliseconds to complete. This does not kill the operation on the server, it is a client-side timeout.
| 版本 | 说明 |
|---|---|
| 1.0.5 | Changed second parameter to an array of options. Pre-1.0.5, the second parameter was a boolean indicating the "justOne" option and there was no safe option. |
| 1.0.9 | Added ability to pass integers to "safe" options (only accepted booleans before) and added "fsync" option. |
| 1.0.9 | The return type was changed to be an array containing error information if the "safe" option is used, otherwise it is a boolean as before. |
| 1.0.11 | Disconnects on "not master" errors if "safe" is set. |
| 1.2.0 | Added timeout option. |
| 1.3.0 |
The options parameter does no longer accept
just a boolean to signify "justOne". Instead, this now has to be done
with array('justOne' => true).
|
Example #1 MongoCollection::remove() with justOne example
<?php
$radioactive = $db->radioactive;
// count how much more plutonium there is
$remaining = $radioactive->count(array('type' => 94));
$halflife = $remaining/2;
// remove half of it
while ($halflife > 0) {
$radioactive->remove(array('type' => 94), array("justOne" => true));
$halflife--;
}
?>