Saving PHP sessions in Postgres Database.

Disclaimer: Storing sessions in PHP via files(default) and other caching systems like Memcache / memcached / Redis is definitely faster but there was this use case where I had to use RDBMS for storing sessions and hence this. Use this only when it is a strict requirement to save sessions in a relational database

Single file (PGSessions.php)

Requirements:

• PostgreSQL 9.5+ [Dependency on using UPSERT]

• PHP 7.0+ (Might be compatible with 5.4 plus but not tested)

• \PDO Connected Database Object

• Create "sessions" database as provided below.

    CREATE TABLE "sessions" (
    "id" TEXT NOT NULL UNIQUE,
    "last_updated" BIGINT NOT NULL,
    "expiry" bigint NOT NULL,
    "data" TEXT NOT NULL);
    CREATE INDEX "valid_sessions" ON "sessions"("id");
    CREATE INDEX "nonexpired_sessions" ON "sessions"("id","expiry");
  

Steps to use:

• Pass the PDO Connected to the class constructor.

• Define SESSION_DURATION constants to set session expiry.

        SESSION_DURATION    -> Expiry of sessions in number of seconds.
  

Demo

require_once 'PGSessions.php';

$pdo_connection = new PDO(...);

use \PGSessions\PGSessions;
$sessions_handler = new PGSessions($pdo_connection);
session_set_save_handler($sessions_handler, true);
session_name('MySessionName');
session_start();
session_regenerate_id(true);

$_SESSION['something'] = 'foo';
$_SESSION['something_else'] = 'bar';
echo session_id(),'<br/>',$_SESSION['something'],'<br />',$_SESSION['something_else'] ;
/*
Rest of your script
.
.
.
.
.
.
.
.
.
.
Before ending your script
*/
session_write_close();
//Note that session_write_close is not REQUIRED to be called on each page since we register_shutdown_function=true (second parameter = true in  session_set_save_handler).