Mysql2 error

gistfile1.txt

# MySQL db, Rails 3.2, Ruby 1.8.7
# Works for anything other than 1 in: `students`.`sen_status_id` IN ...
# sens_status_id is an int column.
# There are significantly more rows with 1 than anything else, some are NULL, others are 2 and 3

  Student Load (38.5ms)  SELECT DISTINCT students.* FROM `students` LEFT JOIN klasses_students ON ( klasses_students.student_id = students.id ) WHERE `students`.`sen_status_id` IN (1, 2) AND `klasses_students`.`klass_id` IN (1, 2, 3, 4, 5, 6, 7, 8, 9) AND (archived = 0) ORDER BY firstname ASC
Mysql2::Error: Lost connection to MySQL server during query: SELECT DISTINCT students.* FROM `students` LEFT JOIN klasses_students ON ( klasses_students.student_id = students.id ) WHERE `students`.`sen_status_id` IN (1, 2) AND `klasses_students`.`klass_id` IN (1, 2, 3, 4, 5, 6, 7, 8, 9) AND (archived = 0) ORDER BY firstname ASC
Completed 500 Internal Server Error in 85ms

ActiveRecord::StatementInvalid (Mysql2::Error: Lost connection to MySQL server during query: SELECT DISTINCT students.* FROM `students` LEFT JOIN klasses_students ON ( klasses_students.student_id = students.id ) WHERE `students`.`sen_status_id` IN (1, 2) AND `klasses_students`.`klass_id` IN (1, 2, 3, 4, 5, 6, 7, 8, 9) AND (archived = 0) ORDER BY firstname ASC):
  app/controllers/reports_controller.rb:401:in `multiple'

# This on the other hand, goes through untroubled:

  Student Load (7.7ms)  SELECT DISTINCT students.* FROM `students` LEFT JOIN klasses_students ON ( klasses_students.student_id = students.id ) WHERE `students`.`sen_status_id` IN (2, 3) AND `klasses_students`.`klass_id` IN (1, 2, 3, 4, 5, 6, 7, 8, 9) AND (archived = 0) ORDER BY firstname ASC

# relevant bits from reports_controller.rb :

@students = Student.not_archived.where( conditions ).joins( joins ).select('DISTINCT students.*').order('firstname ASC')


line 401:     @students.each do |s|