How can we retrieve data from a database table using PH…

The steps for retrieving data from a database table using PHP are as follows:

1. establish a connection to a MySQL database
2. create a new instance of PDO()

$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "database";

// 使用mysqli连接数据库
$conn = mysqli_connect($servername, $username, $password, $dbname);

// 使用PDO连接数据库
$dsn = "mysql:host=$servername;dbname=$dbname";
$conn = new PDO($dsn, $username, $password);

1. Choose

$sql = "SELECT * FROM table_name";

1. execute a query using MySQLi
2. Execute the query using the connection.

// 使用mysqli执行查询
$result = mysqli_query($conn, $sql);

// 使用PDO执行查询
$result = $conn->query($sql);

1. Retrieve an associative array of fetched data using MySQLi.
2. Fetch the result.

// 使用mysqli处理结果
while ($row = mysqli_fetch_assoc($result)) {
    // 处理每一行数据
    echo $row['column_name'];
}

// 使用PDO处理结果
while ($row = $result->fetch()) {
    // 处理每一行数据
    echo $row['column_name'];
}

Before handling the results, ensure that you are connected to the database and the query statement has been executed successfully.