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Php 简单SELECTSQL语句返回空_Php_Mysql - Fatal编程技术网

Php 简单SELECTSQL语句返回空

Php 简单SELECTSQL语句返回空,php,mysql,Php,Mysql,我是php新手,我正在尝试从数据库中的表中获取所有数据(目前) include_once("dbconnect.php"); $stmt = $dbh->prepare("SELECT * FROM temperature"); while($row = $stmt->fetch()) { print_r($row); echo $row; } dbconnect.php-这在其他脚本中使用,效果很好,但只是为了以防万一: $hostname = 'loc

我是php新手,我正在尝试从数据库中的表中获取所有数据(目前)

include_once("dbconnect.php");  
$stmt = $dbh->prepare("SELECT * FROM  temperature");

while($row = $stmt->fetch())
{
    print_r($row);
    echo $row;

}
dbconnect.php-这在其他脚本中使用,效果很好,但只是为了以防万一:

$hostname = 'localhost';

$username = 'root';

$password = '123456';

$dbh = new PDO("mysql:host=$hostname;dbname=arduinotest", $username, $password);
无论是
print\u r($row)
echo($row)显示任何内容

我错过了什么

表名正确,请尝试使用dbname.tablename

编辑:当
打印时($dbh->errorInfo())用于输出
数组([0]=>00000[1]=>[2]=>)
我缺少
$stmt->execute()


感谢Sebas的注意

桌子是空的吗?如果不是,错误消息是什么?表不是空的,没有错误消息,只有空白页。如果我使用print_r($dbh->errorInfo());它输出数组([0]=>00000[1]=>[2]=>)是的,就是这样xD谢谢