The MongoDB class
(PECL mongo >=0.9.0)
Введение
Instances of this class are used to interact with a database. To get a database:
Пример #1 Selecting a database
<?php
$m = new MongoClient(); // connect
$db = $m->selectDB("example");
?>
A few unusual, but valid, database names: "null", "[x,y]", "3", "\"", "/".
Unlike collection names, database names may contain "$".
Обзор классов
$preserve_cloned_files = FALSE
[, bool $backup_original_files = FALSE
]] )Предопределенные константы
MongoDB Log Levels
MongoDB::PROFILING_OFF-
0 - Profiling is off.
MongoDB::PROFILING_SLOW-
1 - Profiling is on for slow operations (>100 ms).
MongoDB::PROFILING_ON-
2 - Profiling is on for all operations.
Fields
- w
- 1
-
The number of servers to replicate a change to before returning success. Inherited by instances of MongoCollection derived from this. w functionality is only available in version 1.5.1+ of the MongoDB server and 1.0.8+ of the driver.
w is used whenever you need to adjust the acknowledgement level (MongoCollection::insert(), MongoCollection::update(), MongoCollection::remove(), MongoCollection::save(), and MongoCollection::ensureIndex() all support this option). With the default value (1), an acknowledged operation will return once the database server has the operation. If the server goes down before the operation has been replicated to a secondary, it is possible to lose the operation forever. Thus, you can specify w to be higher than one and guarantee that at least one secondary has the operation before it is considered successful.
For example, if w is 2, the primary and one secondary must have a record of the operation or the driver will throw a MongoCursorException. It is tempting to set w to the total number of secondaries + primary, but then if one secondary is down the operation will fail and an exception will be thrown, so usually w=2 is safest (primary and one secondary).
- wtimeout
- 10000
-
The number of milliseconds to wait for MongoDB::$w replications to take place. Inherited by instances of MongoCollection derived from this. w functionality is only available in version 1.5.1+ of the MongoDB server and 1.0.8+ of the driver.
Unless wtimeout is set, the server waits forever for replicating to w servers to finish. The driver defaults to waiting for 10 seconds, you can change this value to alter its behavior.
Смотрите также
MongoDB core docs on » databases.
Содержание
- MongoDB::authenticate — Log in to this database
- MongoDB::command — Execute a database command
- MongoDB::__construct — Creates a new database
- MongoDB::createCollection — Creates a collection
- MongoDB::createDBRef — Creates a database reference
- MongoDB::drop — Drops this database
- MongoDB::dropCollection — Drops a collection [deprecated]
- MongoDB::execute — Runs JavaScript code on the database server [deprecated]
- MongoDB::forceError — Creates a database error
- MongoDB::__get — Gets a collection
- MongoDB::getCollectionInfo — Returns information about collections in this database
- MongoDB::getCollectionNames — Gets an array of names for all collections in this database
- MongoDB::getDBRef — Fetches the document pointed to by a database reference
- MongoDB::getGridFS — Fetches toolkit for dealing with files stored in this database
- MongoDB::getProfilingLevel — Gets this database's profiling level
- MongoDB::getReadPreference — Get the read preference for this database
- MongoDB::getSlaveOkay — Get slaveOkay setting for this database
- MongoDB::getWriteConcern — Get the write concern for this database
- MongoDB::lastError — Check if there was an error on the most recent db operation performed
- MongoDB::listCollections — Gets an array of MongoCollection objects for all collections in this database
- MongoDB::prevError — Checks for the last error thrown during a database operation
- MongoDB::repair — Repairs and compacts this database
- MongoDB::resetError — Clears any flagged errors on the database
- MongoDB::selectCollection — Gets a collection
- MongoDB::setProfilingLevel — Sets this database's profiling level
- MongoDB::setReadPreference — Set the read preference for this database
- MongoDB::setSlaveOkay — Change slaveOkay setting for this database
- MongoDB::setWriteConcern — Set the write concern for this database
- MongoDB::__toString — The name of this database
Коментарии
based on what I've read and then applied, you don't have to specifically create a database or table, you just initialize it.
Indeed, files are not being written inside /data/db, but they will the first moment you start adding data.
So, I'm taking as an example Twitter, with no db defined, I'm still going to have the db available if I run this code:
<?php
define('TWITTER_API_VERSION', 1);
date_default_timezone_set("Europe/Dublin");
try
{
$m = new Mongo(); // connect
$db = $m->selectDB("example");
}
catch ( MongoConnectionException $e )
{
echo '<p>Couldn\'t connect to mongodb, is the "mongo" process running?</p>';
exit();
}
$updates = file_get_contents( "http://api.twitter.com/". TWITTER_API_VERSION ."/statuses/public_timeline.json" );
$updates = json_decode( $updates );
if ( $updates && is_array( $updates ) && count( $updates ) )
{
foreach ( $updates as $update )
{
$db->users->insert( $update );
}
}
?>
Hope this was helpful!
Good luck!
Vladimir Ghetau
With Mongo it'll automatically create the collection, so just start using it and it'll do the creation itself.
In other words... just use SelectCollection, if it doesn't exist, it will after that so you can drop it.
mongo extension is deprecated.
pecl install mongodb