deleteCourses :: WithConfig ()
deleteCourses = do
  runDb $ deleteWhere [CourseId >. toSqlKey 0] 
deleteCourses :: WithConfig ()
deleteCourses = do
  runDb $ deleteWhere [CourseId >. toSqlKey 0] 
deleteCourses = do
  runDb $ deleteWhere [CourseId >. toSqlKey 0] 