我有一张叫做Students另一张叫的桌子Enrollment.我想获得特定学生的记录以及他们注册的课程.
我使用过MySQL功能GROUP_CONCAT,这在SQL Server中显然是不可用的,这正是我现在正在使用的.当我执行我的存储过程时,我收到一个错误
将varchar值','转换为数据类型int时转换失败.
我为什么要这个?当我在SQL Server Management Studio中执行它时,我给存储过程一个值1.
这是我的存储过程:
ALTER PROCEDURE [dbo].[GetStudentDetails]
@studentID int
AS
BEGIN
SET NOCOUNT ON;
SELECT
s.studentId, s.firstName, s.lastName,
STUFF((SELECT ',' + e.courseId
FROM dbo.Enrollment as e
FOR XML PATH ('')), 1, 1, '') AS enrolledCourses
FROM dbo.Students as s
WHERE s.studentId = @studentID
END
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我究竟做错了什么?
我的 WPF 应用程序的主窗口中有一个登录表单。如果用户登录成功,我想打开HomeWindow。我的问题是我需要将 adminID 变量从 MainWindow 传递到 HomeWindow。我怎样才能做到这一点?
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
private void btnLogin_Click(object sender, RoutedEventArgs e)
{
int errors = 0;
if (txtUsername.Text == "")
{
lblUsernameStatus.Content = "This field is required.";
errors = errors + 1;
}
if (txtPassword.Text == "")
{
lblPasswordStatus.Content = "This field is required.";
errors = errors + 1;
}
if (errors == 0)
{
Administrator TryLogin = new Administrator();
if (TryLogin.VerifyUser(txtUsername.Text, txtPassword.Text))
{
HomeWindow …Run Code Online (Sandbox Code Playgroud) 创建可以在文件之间使用甚至是对象到对象的变量的最佳方法是什么?例:
设置文件将包含如下数组:
<?php
$config = array(
'key1' => 'val1',
'key2' => 'val2'
);
?>
<?php
class config {
function get_data($file){
require_once('config/'.$file.'.php');
foreach($config as $key => $val){
$this->$key = $val;
}
}
}
?>
Run Code Online (Sandbox Code Playgroud) 我正在尝试编写一个显示错误的类。我希望能够在一条线上完成。所以这就是我用来显示错误的内容:
$this->error->title("Error Title")->message("This is an error message")->redirect('home')->display();
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这是我的课:
<?php
class Error {
var $title;
var $message;
var $redirect;
function title($title){
$this->title = $title;
}
function message($message){
$this->message = $message;
}
function redirect($redirect){
$this->redirect = $redirect;
}
function display(){
$CI &= get_instance();
$CI->template->overall_header($this->title);
$data = array(
'error_title' => $this->title,
'error_message' => $this->message
);
if(isset($this->redirect)){
$data['redirect'] = $this->redirect;
}
$CI->load->view('error_body', $data);
}
}
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这是我得到的错误:
Fatal error: Call to a member function message() on a non-object in ...\application\frontend\controllers\members\login.php on line 128
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为什么我会在 message() …