[英]How to convert mysqli_query result to int?
目前我正在開發一個移動圖書館應用程序,它需要借書。 我希望能夠查看與可用圖書總數相比已借出的圖書數量。 我正在努力將mysqli_query
結果轉換為整數以與可用書籍總數進行比較。 如果這是一個簡單的答案(我很新),我深表歉意,因為我做了很多挖掘,但找不到可以適應我的場景的答案。
<?php
require "conn.php";
$userID = "2";
$book_id = "1";
$mysql_qry = "select COUNT(*) from books_checked_out where bookID=$book_id";
$result = mysqli_query($conn, $mysql_qry);
//Somewhere here convert the $result into $quantity, which would be an int
if($quantity >= 2) {
echo "more books checked out than in stock";
}
else if($quantity < 2) {
echo "less books checked out than in stock";
}
?>
任何幫助表示贊賞,謝謝!
這將工作
$result = $result->fetch_array();
$quantity = intval($result[0]);
你可以這樣做:
$userID = "2";
$book_id = "1";
$mysql_qry = "select COUNT(*) as quantity from books_checked_out where bookID=$book_id";
$result = mysqli_query($conn, $mysql_qry);
$row = mysqli_fetch_array($result, 'MYSQLI_ASSOC'); // Use something like this to get the result
$quantity = $row['quantity'];
if($quantity >= 2) {
echo "more books checked out than in stock";
}
else if($quantity < 2) {
echo "less books checked out than in stock";
}
?>
這應該有效。 請注意 SQL 注入。 另外,我對庫存書籍的數據庫進行了瘋狂的猜測,這將需要更改。
require "conn.php";
$userID = "2";
$book_id = "1";
$mysql_qry = "SELECT
(SELECT COUNT(*) FROM books_checked_out WHERE bookID='" . $book_id . "') as num1,
(SELECT COUNT(*) FROM books_in_stock WHERE bookID='" . $book_id . "') as num2";
$result = mysqli_query($conn, $mysql_qry);
$quantity = mysqli_fetch_assoc($result);
if($quantity['num1'] >= 2) {
echo "more books checked out than in stock";
}
else {
echo "less books checked out than in stock";
}
//If you want to see the difference you can do something like this.
echo "Checked Out" . $quantity['num1'] . '<br/>';
echo "In Stock" . $quantity['num2'] . '<br/>';
嘗試使用intval("0".$row['quantity'])
這會將您的數量轉換為整數。
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