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Detailed tutorial on establishing a database connection using MySQLi in PHP
Detailed tutorial on establishing a database connection using MySQLi in PHP
Jun 04, 2024 pm 01:42 PM
How to use MySQLi to establish a database connection in PHP: Include MySQLi extension (require_once) Create connection function (function connect_to_db) Call connection function ($conn = connect_to_db()) Execute query ($result = $conn->query( )) Close the connection ($conn->close())
Use MySQLi in PHP to establish a database connection
Introduction
MySQLi is an extension in PHP used to interact with the MySQL database. It provides a simple and efficient way to establish a database connection and execute queries. This article will provide a detailed guide on how to establish a database connection using MySQLi in PHP, including practical examples.
Prerequisites
Before continuing, make sure the following prerequisites are met:
- PHP Installation and Configuration
- MySQL Databases and Servers
- MySQLi extension enabled or installed
Step 1: Include the MySQLi extension
First, include the MySQLi extension to your In PHP script:
<?php require_once 'path/to/mysqli_connect.php'; ?>
Step 2: Create connection function
In order to reuse the connection code, create a function to establish the MySQLi connection:
<?php
function connect_to_db() {
$hostname = 'localhost';
$username = 'root';
$password = '';
$database = 'my_database';
$conn = new mysqli($hostname, $username, $password, $database);
if ($conn->connect_error) {
die("連接失敗: " . $conn->connect_error);
}
return $conn;
}
?>Step 3: Call the connection function
In your script, obtain the MySQLi connection by calling the connect_to_db() function:
<?php $conn = connect_to_db(); ?>
Step 4: Execute the query
Now, you can use the connection object to execute MySQL queries:
<?php
$result = $conn->query("SELECT * FROM users");
if (!$result) {
die("查詢失敗: " . $conn->error);
}
// 處理查詢結(jié)果...
?>Step 5: Close the connection
Finally, close at the end of the script MySQLi connection to release resources:
<?php $conn->close(); ?>
Practical case
The following is a simple example of how to use MySQLi to connect to a database and retrieve data:
<?php
$conn = connect_to_db();
$result = $conn->query("SELECT * FROM users");
while ($row = $result->fetch_assoc()) {
echo $row['id'] . ' ' . $row['name'] . '<br>';
}
$conn->close();
?>Conclusion
By following these steps, you can easily establish a database connection and execute MySQL queries using MySQLi in PHP. By reusing connection functions and releasing resources correctly, you can ensure a stable and efficient database connection.
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