MYSQL returning duplicate rows

Question

I have a Database table in MYSQL, it looks like this:

Project_ID  user_ID  name
11          1        fred
11          2        rick
11          1        fred         


        

Answer 1

Use DISTINCT

  SELECT DISTINCT user_ID
       , verschil_ma 
    FROM project_uren 
   WHERE project_ID = 11
GROUP BY user_ID