MongoDB connectivity

This library implements MongoDB connectivity via its binary protocol. It has no dependencies on the PHP extension.

Examples

Finding documents inside a collection:

use com\mongodb\{MongoConnection, ObjectId};
use util\cmd\Console;

$c= new MongoConnection('mongodb://localhost');
$id= new ObjectId(...);

// Find all documents
$cursor= $c->collection('test.products')->find();

// Find document with the specified ID
$cursor= $c->collection('test.products')->find($id);

// Find all documents with a name of "Test"
$cursor= $c->collection('test.products')->find(['name' => 'Test']);

foreach ($cursor as $document) {
  Console::writeLine('>> ', $document);
}

Inserting a document into a collection:

use com\mongodb\{MongoConnection, Document};
use util\cmd\Console;

$c= new MongoConnection('mongodb://localhost');

$result= $c->collection('test.products')->insert(new Document([
  'name' => 'Test',
  'qty'  => 10,
  'tags' => ['new', 'tested'],
]));
Console::writeLine('>> ', $result);

Updating documents:

use com\mongodb\{MongoConnection, ObjectId};
use util\cmd\Console;

$c= new MongoConnection('mongodb://localhost');
$id= new ObjectId(...);

// Select a single document for updating by its ID
$result= $c->collection('test.products')->update($id, ['$inc' => ['qty' => 1]]);

// Apply to all documents matchig a given filter
$result= $c->collection('test.products')->update(['name' => 'Test'], ['$inc' => ['qty' => 1]]);

Console::writeLine('>> ', $result);

Upserting documents:

use com\mongodb\MongoConnection;
use util\cmd\Console;

$c= new MongoConnection('mongodb://localhost');

$result= $c->collection('test.products')->upsert(['slug' => 'test'], new Document([
  'slug' => 'test',
  'name' => 'Test',
  'qty'  => 10,
  'tags' => ['new', 'tested'],
]));

Console::writeLine('>> ', $result);

Deleting documents:

use com\mongodb\{MongoConnection, ObjectId};
use util\cmd\Console;

$c= new MongoConnection('mongodb://localhost');
$id= new ObjectId(...);

// Select a single document to be removed
$result= $c->collection('test.products')->delete($id);

// Remove all documents matchig a given filter
$result= $c->collection('test.products')->delete(['name' => 'Test']);

Console::writeLine('>> ', $result);

Note: All of the above have used the collection() shortcut which is equivalent to chaining database('test')->collection('products').

Authentication

To authenticate, pass username and password via the connection string, e.g. mongodb://user:pass@localhost. The authentication source defaults to admin but can be set by supplying a path, e.g. mongodb://user:pass@localhost/test.

Both SCRAM-SHA-256 and SCRAM-SHA-1 are supported as authentication mechanisms. Which one is used is negotiated upon connecting with the server / cluster. To explicitely select the authentication mechanism, pass it as part of the connection string, e.g. mongodb://user:pass@localhost?authMechanism=SCRAM-SHA-256.

SSL / TLS

To connect via SSL / TLS, pass ssl=true as connection string parameters, e.g.:

use com\mongodb\MongoConnection;

$c= new MongoConnection('mongodb://localhost?ssl=true');

// Explicit call to connect, can be omitted when using collection()
$c->connect();

Aggregation

The Collection class also features aggregation methods:

• count($filter= [])
• distinct($key, $filter= [])
• aggregate($pipeline)

See https://docs.mongodb.com/manual/reference/command/nav-aggregation/

Commands

To run commands on a given collection, use the run() method:

use com\mongodb\MongoConnection;

$c= new MongoConnection('mongodb+srv://server.example.com');

// A simple connection-wide command without arguments
$result= $c->run('ping')->value();

// A command might return a cursor
$indexes= $c->collection('app.sessions')->run('listIndexes', [], 'read');
foreach ($indexes->cursor() as $index) {
  // ...
}

See https://www.mongodb.com/docs/manual/reference/command/ for a list of commands.

DNS Seed List Connection

Adding in DNS to specify clusters adds another level of flexibility to deployment. Given the following DNS entries:

Record                            TTL   Class    Priority Weight Port  Target
_mongodb._tcp.server.example.com. 86400 IN SRV   0        5      27317 mongodb1.example.com.
_mongodb._tcp.server.example.com. 86400 IN SRV   0        5      27017 mongodb2.example.com.

...the following code will connect to one of the above:

use com\mongodb\MongoConnection;

$c= new MongoConnection('mongodb+srv://server.example.com');
$c->connect();

Sessions

Using a causally consistent session, an application can read its own writes and is guaranteed monotonic reads, even when reading from replica set secondaries.

use com\mongodb\{MongoConnection, ObjectId};
use util\cmd\Console;

$c= new MongoConnection('mongodb+srv://server.example.com?readPreference=secondary');
$session= $c->session();

$id= new ObjectId('...');

// Will write to primary
$collection= $c->collection('test.products');
$collection->update($id, ['$set' => ['qty' => 1]], $session);

// Will read the updated document
$updated= $collection->find($id, $session);

$session->close();

Handling errors

All operations raise instances of the com.mongodb.Error class. Connection and authentication errors can be handled by checking for CannotConnect:

use com\mongodb\{MongoConnection, Error, CannotConnect};
use util\cmd\Console;

$c= new MongoConnection('mongodb+srv://user:pass@mongo.example.com');
try {
  $c->connect();
} catch (CannotConnect $e) {
  // Error during authentication phase, e.g.:
  // - DNS errors
  // - None of the replica set members is reachable
  // - Authentication failed
} catch (Error $e) {
  // Any other error
}

Type mapping

All builtin types are mapped to their BSON equivalents. In addition, the following type mappings are used:

• util.Date => UTC datetime
• util.Bytes => Binary data
• util.UUID => UUID binary data
• com.mongodb.Int64 => 64-bit integer
• com.mongodb.Decimal128 => 128-bit decimal
• com.mongodb.ObjectId => Object ID
• com.mongodb.Timestamp => Timestamp
• com.mongodb.Regex => Regular expression

The deprecated types of the BSON spec are not supported, see http://bsonspec.org/spec.html