Connect to MariaDB database using PHP

MariaDB is an open source relational database management system, which is a branch of MySQL. PHP, as an open source server-side scripting language, is widely used in web development. In many web development projects, you need to use PHP to connect to the MariaDB database in order to store and retrieve data in the web application. This article will introduce how to use PHP to write code to connect to the MariaDB database.

1. Install MariaDB server

Before using PHP to connect to the MariaDB database, you first need to install the MariaDB server. Here we take the CentOS 7 operating system as an example to introduce how to install the MariaDB server.

1. Update the system package list

Use the yum command to update the system package list:

sudo yum update

2. Install the MariaDB server

Execute the following command to install the MariaDB server:

sudo yum install mariadb mariadb-server

3. Start the MariaDB service

Start the MariaDB server:

sudo systemctl start mariadb

4. Set up the MariaDB server Self-start

Start the MariaDB server automatically after booting:

sudo systemctl enable mariadb

2. Create MariaDB user and database

Before connecting to the MariaDB database, you need to create a user and a database. Here we take creating a database named "testdb" and a user named "testuser" as an example.

1. Log in to the MariaDB server

Execute the following command to log in to the MariaDB server:

sudo mysql -u root -p

Here you need to enter the root user password of the MariaDB server.

2. Create database

Execute the following command in the MariaDB command line to create a database named "testdb":

CREATE DATABASE testdb;

3. Create User

Execute the following command in the MariaDB command line to create a user named "testuser" and set the password to "password":

CREATE USER 'testuser'@'localhost' IDENTIFIED BY 'password';

4. Authorized user

Execute the following command in the MariaDB command line to authorize the "testuser" user to access the "testdb" database:

GRANT ALL PRIVILEGES ON testdb.* TO 'testuser'@'localhost';

5. Refresh permissions

Execute the following command in the MariaDB command line to refresh the permissions:

FLUSH PRIVILEGES;

3. Use PHP to connect to the MariaDB database

After completing the creation of the MariaDB server, user, and database, we can use PHP Write code to connect to the MariaDB database and perform queries, inserts, etc.

1. Install PHP

Install PHP in CentOS 7 operating system:

sudo yum install php php-mysql

2. Connect to MariaDB database

In PHP code, you need to use the mysqli_connect() function to connect to the MariaDB database. This function needs to specify the address of the database server, user name, password and the name of the database to be connected.

For example, the following code demonstrates how to connect to a previously created database named "testdb", using a user named "testuser" with a password of "password" on a local address. After the connection is successful, use the mysqli_select_db() function to select the connected database:

<?php
$servername = "localhost";
$username = "testuser";
$password = "password";
$dbname = "testdb";

// Create connection
$conn = mysqli_connect($servername, $username, $password, $dbname);

// Check connection
if (!$conn) {
    die("Connection failed: " . mysqli_connect_error());
}

// Select the database
mysqli_select_db($conn, $dbname);

echo "Connected successfully";
?>

3. Query data

After connecting to the MariaDB database, you can use the mysqli_query() function to execute a SELECT statement query data. This function needs to receive two parameters: the connection object and the query statement to be executed. After executing the query, you can use the mysqli_fetch_assoc() function to obtain the data in the result set.

For example, the following code demonstrates how to query data in a table named "users":

<?php
$servername = "localhost";
$username = "testuser";
$password = "password";
$dbname = "testdb";

// Create connection
$conn = mysqli_connect($servername, $username, $password, $dbname);

// Check connection
if (!$conn) {
    die("Connection failed: " . mysqli_connect_error());
}

// Select the database
mysqli_select_db($conn, $dbname);

// Execute query
$result = mysqli_query($conn, "SELECT * FROM users");

// Loop through result set
while ($row = mysqli_fetch_assoc($result)) {
    echo "Name: " . $row["name"] . " - Email: " . $row["email"] . "<br>";
}

// Close connection
mysqli_close($conn);
?>

4. Insert data

Using PHP to MariaDB The process of inserting data into the database is similar to querying data. You can use the mysqli_query() function to execute an INSERT statement to insert data. This function needs to receive two parameters: the connection object and the INSERT statement to be executed.

For example, the following code demonstrates how to insert a piece of data into a table named "users":

<?php
$servername = "localhost";
$username = "testuser";
$password = "password";
$dbname = "testdb";

// Create connection
$conn = mysqli_connect($servername, $username, $password, $dbname);

// Check connection
if (!$conn) {
    die("Connection failed: " . mysqli_connect_error());
}

// Select the database
mysqli_select_db($conn, $dbname);

// Insert data
$sql = "INSERT INTO users (name, email) VALUES ('John', 'john@example.com')";

if (mysqli_query($conn, $sql)) {
    echo "New record created successfully";
} else {
    echo "Error: " . $sql . "<br>" . mysqli_error($conn);
}

// Close connection
mysqli_close($conn);
?>

Summary:

Using PHP to connect to the MariaDB database can easily be done on the Web Store and retrieve data within the application. Before connecting, you need to install the MariaDB server and create a user and a database. After completion, you can use PHP to write code to connect to the database and perform queries, inserts, etc. It should be noted that when using the mysqli_connect() function to connect to a database, you need to specify the address of the database server, user name, password and the name of the database to be connected. When using the mysqli_query() function to execute a SQL statement, you need to pass the SQL statement as a parameter of the function.

The above is the detailed content of Connect to MariaDB database using PHP. For more information, please follow other related articles on the PHP Chinese website!