Mongo::connectUtilMongo::__construct
(PECL mongo >=0.9.0)
Mongo::__construct — Creates a new database connection object
Description
If no parameters are passed, this connects to "localhost:27017" and returns.
If you elect not to connect immediately ($connect is FALSE), you will need to call connect(), persistConnect(), pairConnect(), or pairPersistConnect() before doing any database operations.
<?php
$mongo = new Mongo("localhost", false);
// throws a MongoException, as $mongo has not been fully initialized yet
$mongo->selectDB("foo")->command(array("distinct" => "bar", "key" => "age"));
// okay
$mongo->connect();
$mongo->selectDB("foo")->command(array("distinct" => "bar", "key" => "age"));
?>
Parameters
- server
-
The server name.
- connect
-
If the constructor should connect to the database now. If this is FALSE, the constructor will return without connecting to the database.
- persistent
-
If the connection should be persistent.
- paired
-
If the connection should be paired.
Return Values
Returns a new database connection object.
Errors/Exceptions
Throws MongoConnectionException if it tries and fails to connect to the database.
Examples
Example #1 Mongo::__construct() paired connection example
This example shows how to connect the driver to a replica pair of Mongo servers.
<?php
// pass a comma-separated list of server names to the constructor
$m = new Mongo("www.example1.com,www.example2.com", false);
$m->pairConnect();
// if the database servers are not running on the default port (27017),
// you'll need to specify the port
$m2 = new Mongo("www.example1.com:12345,www.example.com:54321", false);
$m2->pairConnect();
// you can also do a paired connection in one line of code
$m3 = new Mongo("www.example1.com,www.example.com", true, false, true);
?>
Example #2 Mongo::__construct() persistent connection example
A persistent connection will last for more than one request (usually... milage may vary depending on server). It can save significant time to reuse connections, as creating a connection is a time-intensive process.
A persistent connection is identified by the server string and optional "username" and "password" strings. These strings are arbitrary and should not be sensitive (i.e., a real password). They are merely indended as unique identifiers for a connection.
<?php
// creates a persistent connection
$m1 = new Mongo("localhost", true, true);
// uses the same connection as $m1
$m2 = new Mongo("localhost", false);
$m2->persistConnect();
// creates a new connection
$m3 = new Mongo("127.0.0.1", false);
$m3->persistConnect();
// creates a new connection
$m4 = new Mongo("127.0.0.1:27017", false);
$m4->persistConnect();
// creates a new connection
$m5 = new Mongo("localhost", false);
$m5->persistConnect("foo");
// uses the $m5 connection
$m6 = new Mongo("localhost", false);
$m6->persistConnect("foo");
// creates a new connection
$m7 = new Mongo("localhost", false);
$m7->persistConnect("foo", "bar");
?>
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