Querying SQL Server from a Web Application - Basics for Beginners

Web applications often need to interact with databases to retrieve, update, and display data. In this beginner's guide, we'll explore the basics of querying SQL Server from a web application using PHP. We'll cover essential steps and provide sample PHP code examples to help you get started.

Prerequisites

Before getting started, make sure you have the following prerequisites:

• Web Server: You need a web server (e.g., Apache) to run PHP scripts.
• PHP: Ensure PHP is installed on your web server. You can download PHP from the official website.
• SQL Server: Have access to a SQL Server instance and the necessary credentials.

Connecting to SQL Server with PHP

To connect to SQL Server from a web application, you can use the SQLSRV extension for Microsoft SQL Server in PHP. Here's a PHP code snippet to establish a connection:

$serverName = "your_server";
$connectionOptions = array(
    "Database" => "your_database",
    "Uid" => "your_username",
    "PWD" => "your_password"
);
// Establishes the connection
$conn = sqlsrv_connect($serverName, $connectionOptions);
if ($conn === false) {
    die(print_r(sqlsrv_errors(), true));
} else {
    echo "Connected to SQL Server.";
}
?>    

Executing SQL Queries

With a connection in place, you can execute SQL queries using PHP. Here's an example of executing a SELECT query and displaying the results:

$sql = "SELECT * FROM YourTable";
$query = sqlsrv_query($conn, $sql);
if ($query === false) {
    die(print_r(sqlsrv_errors(), true));
}
while ($row = sqlsrv_fetch_array($query, SQLSRV_FETCH_ASSOC)) {
    // Display data or process results here
}
?>    

What's Next?

You've learned the basics of querying SQL Server from a web application using PHP. To become proficient, you can explore more advanced topics, such as handling user input, executing parameterized queries, data manipulation, and building dynamic web pages that interact with SQL Server databases.

PHP is a versatile language for developing web applications that seamlessly connect to and retrieve data from SQL Server databases.