  def remove_application(users)

    return if users.nil? or users.empty?

    array = ["(xtype='#{Comment::XTYPE_APPLY}')"]
    array << "(item_id=#{self.item_id})"

    user_con_a = []
    users.each do |user_id|
      user_con_a << "(user_id=#{user_id})"
    end

    array << '(' + user_con_a.join(' or ') + ')'

    Comment.destroy_all(array.join(' and '))
 end
The software constructs all or part of an SQL command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended SQL command when it is sent to a downstream component.