A conceptual data schema is four tables and a description of the dependencies between them:
Notes:
- sequence number of the response in the survey - used only to form a queryset when displaying the page with the survey
- name of the survey participant registered on the site - it is filled out only for registered users (non-registered users can also vote and comment). Registered users may suggest creating new polls, but we will not discuss such subtleties in this article.
Dependencies:
- Each survey (a row in the Polls table) corresponds to 2 or more answers, i.e. rows in table Answers
- Each answer (a row in the Answers table) corresponds to 0 or more comments, i.e. rows in the Comments table
- If the site visitor voted for the first time, a new row is created for him in the Visiters table. Users are identified by ip address
- After each vote, the number of votes cast for the selected answer in the survey increases by 1
- The site must remember what answers each visitor gave and what comments he left: each user comment is written in a new row of the Comments table