PHP调用mysql函数出错
<html>
<head>
<title>Book-O-Rama Search Result</title>
</head>
<body>
<h1>Book-O-Rama Search Results</h1>
<?
$searchtype = $_POST['searchtype'];
$searchterm = trim($_POST['searchterm']);
if (!$searchtype || !$searchterm)
{
echo 'You have not entered search details. Please go back and try again.';
exit;
}
if (!get_magic_quotes_gpc())
{
$searchtype = addslashes($searchtype);
$searchterm = addslashes($searchterm);
}
$db = new mysqli('localhost', 'bookorama', 'bookorama123', 'books');
if (mysqli_connect_error())
{
echo 'Error: Could not connect to database. Please try again later.';
exit;
}
$db->select_db("books");
//$query = "select * from books where ".$searchtype." like '%".$searchterm."%'";
$query = "select * from books where ". $searchtype."="."'$searchterm'" ;
//$query = "select * from books";
echo "$query\n";
$result = $db->query($query);
$num_results = $result->num_rows;
echo "<p>Number of books found: ".$num_results."</p>";
for ($i = 0; $i < $num_results; $i++)
{
/* 此段被注释的代码运行出错,错误在于$result->fetch_assoc();
$result->fetch_assoc();
echo "<p><strong>".($i+1).". Title: ";
echo htmlspecialchars(stripslashes($row['title']));
echo "</strong><br />Author: ";
echo stripslashes($row['author']);
echo "<br