Question: I am trying to run my Django server via 'python manage.py runserver' on a github repository i cloned and always get this runtime error message:

> 
> class AbstractBaseUser(models.Model):
> 
> 
> RuntimeError: \_\_\_\_class\_\_\_\_ not set defining 'AbstractBaseUser' as <'class 'django.contrib.auth.base\_user.AbstractBaseUser'>. Was \_\_\_\_classcell\_\_\_\_ propagated to type.\_\_\_\_new\_\_\_\_?
> 
> 
> 

Details of installed packages in my virtual environment are:
Django 1.9 |
django-crispy-forms 1.6.0 |
django-markdown-deux 1.0.5 |
django-pagedown 0.1.1 |
markdown2 2.3.1 |
olefile 0.46 |
Pillow 7.1.1 |
pip 19.2.3 |
setuptools 41.2.0 |

I am using python version 3.8.1

please does anyone have any suggestions on how to solve this error. Thank you.

Answer: 
Since you tag SQL Server 2008

```
WITH CTE AS
(
  SELECT *
  FROM
  (
    VALUES
    (1, 'X', 'CSE-1201'),
    (3, 'Y', 'CSE-1201'),
    (1, 'X', 'EEE-1201')
  ) T(StudentId, StudentName, CourseName)
)
SELECT StudentId, 
       StudentName,
       STUFF(
             (
               SELECT ',' + CourseName 
               FROM CTE T 
               WHERE StudentId = TT.StudentId
               FOR XML PATH('')
             )
            , 1, 1,'') Result
FROM CTE TT
GROUP BY StudentId, StudentName;

```

But remember, you should upgrade right now. [End support SQL Server 2008](https://learn.microsoft.com/en-us/support/sql/end-support-sql-server-2008)
For MySql try,

```
    SELECT StudentId, StudentName, dbo.GROUP_CONCAT(CourseName) 
          FROM TableName 
          GROUP BY StudentId, StudentName

```

For SQL Server try, 

```
select StudentId, StudentName, stuff((select '; ' + a.CourseName
          from TableName a
           Group By StudentId, StudentName
          for xml path ('')
         ), 1, 2, '')  as CourseNames

```