Chris@909: class AddUniqueIndexOnMembers < ActiveRecord::Migration
Chris@909:   def self.up
Chris@909:     # Clean and reassign MemberRole rows if needed
Chris@909:     MemberRole.delete_all("member_id NOT IN (SELECT id FROM #{Member.table_name})")
Chris@909:     MemberRole.update_all("member_id =" +
Chris@909:       " (SELECT min(m2.id) FROM #{Member.table_name} m1, #{Member.table_name} m2" +
Chris@909:       " WHERE m1.user_id = m2.user_id AND m1.project_id = m2.project_id" +
Chris@909:       " AND m1.id = #{MemberRole.table_name}.member_id)")
Chris@909:     # Remove duplicates
Chris@909:     Member.connection.select_values("SELECT m.id FROM #{Member.table_name} m" +
Chris@909:       " 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@909:         Member.delete_all(["id = ?", i])
Chris@909:       end
Chris@909: 
Chris@909:     # Then add a unique index
Chris@909:     add_index :members, [:user_id, :project_id], :unique => true
Chris@909:   end
Chris@909: 
Chris@909:   def self.down
Chris@909:     remove_index :members, [:user_id, :project_id]
Chris@909:   end
Chris@909: end