Class 11: Modeling, continued
Held:
We continue to consider issues of modeling data, in both Rails and in SQL.
Preliminaries
Overview
- SQL basics
- Lab
Related Pages
Updates
News / Etc.
- Apologies for the late start today.
- Please let me know when you notice problems on the Web site. I think I’ve fixed most of them. (Okay, something is massively wrong with the generation of readings in the schedule, but that turns out to be a programming problem I don’t have time to address.)
Upcoming Work
- Reading journal for class 12 due Monday night.
- The last programming project to be posted tonight, due a week from Tuesday.
Good things to do
Note: I do not do extra credit in two-credit classes.
Academic
- Convocation today.
- CS table Tesday
- CS extras Thursday
Data Modeling
- How do we generally model data in these kinds of applications? (Conceptually, rather than what code do we use.)
- We normally say that we use a “relational” model. What does “relation” mean here?
- What general kinds of relationships are there between relations? (and what are examples of each)?
- Why do we use a DBMS rather than managing things by ourselves?
An Exercise
- LibraryThing is a shared “keep track of my books” SaaS.
- For LibraryThing, what relations (tables) do you see as useful? How do you represent them?