original_string: protected function course_students_query_filter($prefix = false) {
          global $DB;
  
          if ($prefix) {
              $prefix = $prefix . '.';
          }
  
          // Check the amount of student logs in the 4 previous weeks.
          list($studentssql, $studentsparams) = $DB->get_in_or_equal($this->get_students(), SQL_PARAMS_NAMED);
          $filterselect = $prefix . 'courseid = :courseid AND ' . $prefix . 'userid ' . $studentssql;
          $filterparams = array('courseid' => $this->course->id) + $studentsparams;
  
          return array($filterselect, $filterparams);
      }
code: protected function course_students_query_filter($prefix = false) {
          global $DB;
  
          if ($prefix) {
              $prefix = $prefix . '.';
          }
  
          // Check the amount of student logs in the 4 previous weeks.
          list($studentssql, $studentsparams) = $DB->get_in_or_equal($this->get_students(), SQL_PARAMS_NAMED);
          $filterselect = $prefix . 'courseid = :courseid AND ' . $prefix . 'userid ' . $studentssql;
          $filterparams = array('courseid' => $this->course->id) + $studentsparams;
  
          return array($filterselect, $filterparams);
      }
code_tokens: protected function course_students_query_filter ( $ prefix = false ) { global $ DB ; if ( $ prefix ) { $ prefix = $ prefix . '.' ; } // Check the amount of student logs in the 4 previous weeks. list ( $ studentssql , $ studentsparams ) = $ DB -> get_in_or_equal ( $ this -> get_students ( ) , SQL_PARAMS_NAMED ) ; $ filterselect = $ prefix . 'courseid = :courseid AND ' . $ prefix . 'userid ' . $ studentssql ; $ filterparams = array ( 'courseid' => $ this -> course -> id ) + $ studentsparams ; return array ( $ filterselect , $ filterparams ) ; }
docstring: Returns the query and params used to filter the logstore by this course students.
  
  @param string $prefix
  @return array
docstring_tokens: Returns the query and params used to filter the logstore by this course students .