[英]Shopping cart in php (mysql_num_rows)
我正在嘗試用php做購物車。
我收到以下錯誤
“警告:mysql_num_rows()期望參數1為資源,在第19行的C:\\ wamp \\ www \\ shoppingCart \\ cart.php中給出的字符串”,並且返回沒有產品。
代碼中的錯誤在第19行:
if(mysql_num_rows($get)==0)[
<?php
session_start();
$page='index.php';
$server="localhost";
$username="root";
$password="";
$database="jennifer_db";
$conn = new mysqli($server, $username, $password, $database);
if($conn->connect_error){
die("Connection failed: " .$conn->Connect_error);
}
function products(){
$get='mysql_query("select Product_ID, Product_name, Product_desc,
Product_price from products where quantity>0 order by id desc")';
if(mysql_num_rows($get)== 0){
echo "There ae no products to display!";
}
else{
echo "Success!";
}
}
?>
您正在混合mysqli
和mysql
函數。 請使用mysqli
或PDO
我在您的代碼中做了一些修改(我使用mysqli),我認為它應該可以工作,請查看注釋:
session_start();
$page = 'index.php';
$server = 'localhost';
$username = 'root';
$password = '';
$database = 'jennifer_db';
// this is the connection object
$mysqli = new mysqli($server, $username, $password, $database);
// if we have an error we abort
if ($mysqli->connect_errno)
die('Connection failed: ' . $mysqli->connect_error);
function products(&$conn)
{
// we pass $conn to this function and make the query
// note that only the SQL query string should be in ""
$result = $conn->query("select Product_ID, Product_name, Product_desc, Product_price from products where quantity > 0 order by id desc");
if ($result)
{
// checking row count
echo (!$result->num_rows ? 'There are no products to display!' : 'Success');
// we close the result set
$result->close();
}
else
echo "Error: {$conn->error}";
}
// call products() here
products($mysqli);
// we close the connection
$conn->close();
有關mysqli的更多信息,請訪問http://php.net/manual/zh/book.mysqli.php
還要簽出PDO並確定要使用哪一個(mysqli或PDO) http://php.net/manual/zh/book.pdo.php
我想您也可以從中學到: http : //davidwalsh.name/php-shorthand-if-else-ternary-operators
希望我能幫上忙。 :)
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