[英]PHP MySQL queries return no results
我通過PHP對MySQL的查詢未返回任何結果。 首先,我嘗試連接並在已知表上進行選擇,但沒有結果。 然后,我嘗試獲取表的列表,再次沒有結果。 當我通過phpMyAdmin查看數據庫時,可以看到表及其內容。 這是我的代碼。 誰能提供一些有關我做錯事情的幫助?
<?php
# /* $ php -f db-connect-test.php */
echo"preparing to connect";
$dbname = '#########';
$dbuser = '#########';
$dbpass = '#########';
$dbhost = 'localhost';
$connect = @mysqli_connect($dbhost, $dbuser, $dbpass, $dbname) or die("Unable to Connect to '$dbhost'");
echo"<html>";
echo"<title>test page</title>";
echo"<body>";
echo"<h2> test page</h2>";
/* check connection */
if ($conn->connect_error) {
die("Connection failed: " . mysqli_connect_error());
}
else{
echo"Successfully Connected <p>";
}
if(mysqli_ping($connection)){
echo "got it<p>";
}
$sql = "SELECT * FROM `announcements`";
$result = mysqli_query($dbname, $sql);
if (mysqli_num_rows($result) > 0) {
// output data of each row
while($row = mysqli_fetch_assoc($result)) {
echo 'date: ' . $row['date'] . '\tTitle: ' . $row['title'] . '\tBody: ' . $row['body'] .'<br />';
}
} else {
echo "0 results<p>";
$sql = "SHOW TABLES";
$result = mysqli_query($dbname, $sql);
if (!$result) {
echo "DB Error, could not list tables<p>";
echo 'MySQL Error: ' . mysqli_error();
}
else{
while ($row = mysqli_fetch_row($result)) {
echo "Table: {$row[0]}<p>";
}
}
}
$conn->close();
echo"</body>";
echo"</html>";
?>
這是我看到的結果:
准備連接
測試頁
連接成功
0結果
DB錯誤,無法列出表
MySQL錯誤:
結果結束
由於某種原因,我無法使MySQL返回錯誤消息。
mysqli_query($dbname, $sql);
第一個參數是您的數據庫鏈接而不是名稱...
mysqli_query($connect, $sql);
另外-不要在連接(最好在任何地方)使用@,因為這樣可以避免錯誤。
更新:也剛剛注意到...
mysqli_ping($connection)
應該是...
mysqli_ping($connect)
您只需要復制並粘貼此代碼
您不必使用$dbname
不必使用$connect
<?php
# /* $ php -f db-connect-test.php */
echo"preparing to connect";
$dbname = '#########';
$dbuser = '#########';
$dbpass = '#########';
$dbhost = 'localhost';
$connect = mysqli_connect($dbhost, $dbuser, $dbpass, $dbname) or die("Unable to Connect to '$dbhost'");
echo"<html>";
echo"<title>test page</title>";
echo"<body>";
echo"<h2> test page</h2>";
/* check connection */
if ($conn->connect_error) {
die("Connection failed: " . mysqli_connect_error());
}
else{
echo"Successfully Connected <p>";
}
if(mysqli_ping($connection)){
echo "got it<p>";
}
$sql = "SELECT * FROM `announcements`";
$result = mysqli_query($connect, $sql);
if (mysqli_num_rows($result) > 0) {
// output data of each row
while($row = mysqli_fetch_assoc($result)) {
echo 'date: ' . $row['date'] . '\tTitle: ' . $row['title'] . '\tBody: ' . $row['body'] .'<br />';
}
} else {
echo "0 results<p>";
$sql = "SHOW TABLES";
$result = mysqli_query($connect, $sql);
if (!$result) {
echo "DB Error, could not list tables<p>";
echo 'MySQL Error: ' . mysqli_error();
}
else{
while ($row = mysqli_fetch_row($result)) {
echo "Table: {$row[0]}<p>";
}
}
}
$conn->close();
echo"</body>";
echo"</html>";
?>
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