php数据库如何建立数据库服务器

<?php
$servername = "localhost";
$username = "root";
$password = "your_password";

// 创建连接
$conn = new mysqli($servername, $username, $password);

// 检测连接
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

// 创建数据库
$sql = "CREATE DATABASE mydatabase";
if ($conn->query($sql) === TRUE) {
    echo "数据库创建成功";
} else {
    echo "Error creating database: " . $conn->error;
}

// 关闭连接
$conn->close();
?>

<?php
$servername = "localhost";
$username = "root";
$password = "your_password";
$dbname = "mydatabase";

// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);

// 检测连接
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

// 查询数据
$sql = "SELECT * FROM your_table";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    // 输出数据
    while($row = $result->fetch_assoc()) {
        echo "字段1: " . $row["column1"]. " - 字段2: " . $row["column2"]. "<br>";
    }
} else {
    echo "0 结果";
}

// 关闭连接
$conn->close();
?>