如何在 Connection NotEstablished 时抛出 SqlException 错误

How to throw SqlException Error as Connection NotEstablished

如何显示SqlConnection没有制作?

public IEnumerable<Employee> GetData()
{
    try
    {
        var x = from n in db.Employee
                select n;
        return x.ToList();
    }
    catch (SqlException sq)
    {
        throw new SqlException();
    }
}

首先,不要在捕获中创建新的异常: 您可以管理异常,例如记录错误并重新抛出以在上层管理错误

public IEnumerable<Employee> GetData()
{
    try
    {
        var x = from n in db.Employee
                select n;
        return x.ToList();
    }
    catch (SqlException ex)
    {
        Logger.Error(ex.Message, ex);
        throw;
    }
}

此代码将在控制器或服务层中。仅作为示例提案,我将返回一个对象,但取决于它是 MVC 应用程序还是 Winforms,消息将以不同的方式流向用户。

public object GetEmployees()
try 
{
   return employees.GetData();
}
catch (Exception ex)
{
   return new "An orror ocurred retrieveing data";
}