chris@37: class AddUniqueIndexOnMembers < ActiveRecord::Migration
chris@37:   def self.up
chris@37:     # Clean and reassign MemberRole rows if needed
chris@37:     MemberRole.delete_all("member_id NOT IN (SELECT id FROM #{Member.table_name})")
chris@37:     MemberRole.update_all("member_id =" +
chris@37:       " (SELECT min(m2.id) FROM #{Member.table_name} m1, #{Member.table_name} m2" +
chris@37:       " WHERE m1.user_id = m2.user_id AND m1.project_id = m2.project_id" +
chris@37:       " AND m1.id = #{MemberRole.table_name}.member_id)")
chris@37:     # Remove duplicates
chris@37:     Member.connection.select_values("SELECT m.id FROM #{Member.table_name} m" +
chris@37:       " WHERE m.id > (SELECT min(m1.id) FROM #{Member.table_name} m1 WHERE m1.user_id = m.user_id AND m1.project_id = m.project_id)").each do |i|
chris@37:         Member.delete_all(["id = ?", i])
chris@37:       end
chris@37:     
chris@37:     # Then add a unique index
chris@37:     add_index :members, [:user_id, :project_id], :unique => true
chris@37:   end
chris@37: 
chris@37:   def self.down
Chris@117:     remove_index :members, [:user_id, :project_id]
chris@37:   end
chris@37: end