如何从数据库中读取并将其传递给会话

I was wondering if anyone could shine a light on how to read from a database and pass it on to a sessions variable. I have tried with a product id and get but it did not work.

I'm looking for the basics on how to approach the issue.

I assume that you need to read from MySQL Database (for example).

First thing to do is reading PHP/MYSQL documentation.

http://www.w3schools.com/php/php_mysql_intro.asp

Second thing is to read about PHP Sessions.

http://www.w3schools.com/php/php_sessions.asp

And for example some code:

// Connect to MySQL Database and select all records from your_table
$conn = new mysqli($servername, $username, $password, $dbname);
if ($conn->connect_error) {
   die("Connection failed: " . $conn->connect_error);
} 
$query = $conn->prepare("SELECT * FROM your_table");
$query->execute();
if($query == TRUE) {
   // query success
}

To store information in $_SESSION variable you need to:

1. Call session_start(); before accessing this variable

2. $_SESSION['your_var'] = 'your_value';