php怎么连接本地mysql数据库服务器

$servername = "localhost";  // MySQL服务器名称，默认为localhost
$username = "root";         // MySQL用户名
$password = "password";     // MySQL密码
$dbname = "database";       // 数据库名称

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

// 检查连接是否成功
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

// 连接成功，可以进行数据库操作

$sql = "SELECT * FROM table_name";
$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";
}

$sql = "INSERT INTO table_name (column1, column2, column3) VALUES ('value1', 'value2', 'value3')";

if ($conn->query($sql) === TRUE) {
    echo "插入成功";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}

$sql = "UPDATE table_name SET column1='new_value' WHERE condition";

if ($conn->query($sql) === TRUE) {
    echo "更新成功";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}

$sql = "DELETE FROM table_name WHERE condition";

if ($conn->query($sql) === TRUE) {
    echo "删除成功";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}