您好我一直在學習本書中的php PHP Solutions Dynamic Web Design Made Easy,並進入了必須使用mysqli api來處理數據庫的部分。寫完連接功能,並運行該腳本,我得到這個錯誤:在嘗試讀取數據時調用非對象的成員函數query()
這是我的代碼:
function dbConnect($usertype , $connectionType = 'mysqli'){
$host = 'localhost';
$db = 'phpsols';
if($usertype == 'read'){
$user = 'psread';
$pwd = 'Aleczandru1989';
}elseif($usertype == 'write'){
$user = 'aleczandru';
$pwd = 'Aleczandru1989';
}else{
exit('Unrecognized type');
}
if($connectionType == 'mysqli'){
return new mysqli($host , $user , $pwd , $db) or die ('Cannot open database');
}else{
try{
return new PDO("mysql:host=$host;dbname=$db", $user, $pwd);
} catch (PDOException $e){
echo 'Cannot connect to database';
exit;
}
}
}
$conn = dbConnect('read');
$sql = 'SELECT * FROM images';
$result = $conn->query($sql) or die(mysqli_error()); //Line 5
$numRows = $result->num_rows;
在這種情況下,5號線是指$結果= $ conn->查詢($ SQL )或死(mysqli_error());. 我在這裏做錯了什麼?