<?php
$sql="SELECT * FROM books";
$result=mysqli_query($conn, $sql); 
//查詢結果迴圈給定陣列
while($row[]=mysqli_fetch_array($result,MYSQLI_ASSOC)){
$str =$row['書籍名稱'];
}

?>

$row=mysqli_fetch_array($result,MYSQLI_ASSOC);
MYSQLI_ASSOC：文字欄位
MYSQLI_NUM：數字欄位
MYSQLI_BOTH：兩者都有