原生php方法mysqli对mysql增删改查

header("Content-type: text/html; charset=utf-8");

$ip = $_REQUEST['ip']; //ip
$time = time(); //创建时间
$content = $_REQUEST['content']; //内容

//连接数据库  数据库host地址 账号 密码 表名
$conn = mysqli_connect("localhost", 'root', "root", 'bd');

//查询数据库
$sql = "select * from bd where ip = '$ip' order by id desc LIMIT 1";
$query = $conn->query($sql);
//$a=[];
while ($row = $query->fetch_array()) {
    echo $row['id'], '
';
    //array_push($a,$row);
}

//插入数据
$sql = "insert into bd (ip,time,content) value ('$ip','$time','$content')";
$result = mysqli_query($conn, $sql);

//修改数据
$sql = "UPDATE table_name SET field1=new-value1, field2=new-value2";
$result = mysqli_query($conn, $sql);
if(!$result)
{
    die('无法更新数据: ' . mysqli_error($conn));
}

//删除数据
$sql = "DELETE FROM runoob_tbl WHERE runoob_id=3";
$result = mysqli_query($conn, $sql);