{"id":270,"date":"2012-08-04T21:52:56","date_gmt":"2012-08-04T13:52:56","guid":{"rendered":"https:\/\/www.techcoil.com\/blog\/?p=270"},"modified":"2018-09-03T22:34:58","modified_gmt":"2018-09-03T14:34:58","slug":"connecting-to-and-disconnecting-from-a-mongodb-server-in-php","status":"publish","type":"post","link":"https:\/\/www.techcoil.com\/blog\/connecting-to-and-disconnecting-from-a-mongodb-server-in-php\/","title":{"rendered":"Connecting to and disconnecting from a MongoDB server in PHP"},"content":{"rendered":"

The first step to manipulate data in the MongoDB ecosystem is to connect to a MongoDB<\/a> server. In php, we can use the Mongo<\/code><\/a> class to help us connect to one or more MongoDB servers. <\/p>\n

For the purpose of this demonstration, let's assume that we had installed a MongoDB server instance as a windows service<\/a> which listens on port 12345<\/strong>. In addition, our PHP web server runs on the same machine as the MongoDB server. <\/p>\n

Connecting to a MongoDB server<\/h3>\n

We can connect to the MongoDB server by specifying the server address and port in the standard connection string format<\/a> and passing the string into the Mongo<\/code> constructor. <\/p>\n

\r\n<?php\r\n$connection = new Mongo('mongodb:\/\/localhost:12345');\r\n?>\r\n<\/pre>\n
Using some functions of the Mongo instance<\/h3>\n
Getting information about the databases managed by the MongoDB server<\/h4>\n
\r\n<?php\r\n$dbArray = $connection->listDBs();\r\necho '<pre>';\r\nprint_r($dbArray);\r\necho '<\/pre>'\r\n?>\r\n<\/pre>\n
The listDBs<\/code> function of the Mongo instance can be used to retrieve some information about the databases that are managed by the MongoDB<\/code> server that we had connected to. The return value is an array that resembles the following format:<\/p>\n
\r\nArray\r\n(\r\n    [databases] => Array\r\n        (\r\n            [0] => Array\r\n                (\r\n                    [name] => admin\r\n                    [sizeOnDisk] => 83886080\r\n                    [empty] => \r\n                )\r\n\r\n            [1] => Array\r\n                (\r\n                    [name] => techcoil\r\n                    [sizeOnDisk] => 83886080\r\n                    [empty] => \r\n                )\r\n\r\n            [2] => Array\r\n                (\r\n                    [name] => local\r\n                    [sizeOnDisk] => 1\r\n                    [empty] => 1\r\n                )\r\n\r\n        )\r\n\r\n    [totalSize] => 167772160\r\n    [ok] => 1\r\n)\r\n<\/pre>\n
Gaining code access to a database instance<\/h4>\n
There are two ways which we can gain access to a database managed by the MongoDB server:<\/p>\n
    \n
  1. \nVia the selectDB function<\/strong><\/p>\n
    \r\n<?php\r\n$techcoilDB = $connection->selectDB('techcoil');\r\n?>\r\n<\/pre>\n<\/li>\n
  2. \nVia the __get magic function<\/strong><\/p>\n
    \r\n<?php\r\n$techcoilDB = $connection->techcoil;\r\n?>\r\n<\/pre>\n<\/li>\n<\/ol>\n
    Both of the code segments retrieve an instance of MongoDB<\/code><\/a> that allow us to manipulate the \"techcoil\" database. <\/p>\n
    Gaining code access to a collection within a database instance<\/h4>\n
    Apart from gaining code access to a database, the Mongo<\/code> class also contains the selectCollection<\/code> function which allows us to gain code access to a collection within the database.<\/p>\n
    \r\n<?php\r\n$userCollection = $collection->selectCollection("techcoil", "User");\r\n?>\r\n<\/pre>\n
    The code segment retrieves a MongoCollection<\/code><\/a> instance and set it to the $userCollection<\/code> variable. We can then manipulate the \"User\" collection that is in the \"techcoil\" database via the $userCollection<\/code> variable.<\/p>\n
    Disconnecting from a MongoDB server<\/h3>\n
    To disconnect from the MongoDB server, we use the same variable which holds the Mongo instance that we had used for connection and execute its close function.<\/p>\n
    \r\n<?php\r\n$connection->close();\r\n?>\r\n<\/pre>\n
    Related posts<\/h3>\n