1. Confirm teams. Review of diagrams. SELECT problems.
Creating Databases
Confirm teams.
Review of diagrams.
SELECT problems.

2. Schedule Next class: present idea for project, including
ER diagram
Data flow diagram
Extra credit opportunity: bulk populate tables
Use files?
Access websites?
Scheduled finals day: present final project

3. Final Presentations Prepare 1-pager: Show Demonstrate
abstract
screen shot(s)
Show
(possibly modified) data flow diagram
(possibly modified) ER diagram
storyboard
Demonstrate
Show at least 1 interesting part of the code
May indicate steps to enhance project
Task for the audience

4. Data flow diagram Who are the (distinct) agents, aka users
For example: customers, administrators
What are the processes, aka tasks
For example: authorize users, remove records…, view some selection, add information..
What is the data store
Could simply list the tables
Note: may be data that isn’t in a table,
File
localStorage

5. Storyboard Make a block for each script (aka file, aka program)
Can label your connect script as being included in every php script
Put in arrows from script to script
Invokes through a form or
Invokes with a hyperlink

6. Documentation Each type of diagram focuses on specific issues.
Data Flow Diagram does not feature sequence of operations.
Entity Relationship features what is in each table and any relations (fields in one table pointing / representing another).
Storyboards feature implementation.
Organizations generally have standards for documentation!

7. SQL UNION
Assume a database with table for full-time faculty and another table for part-time faculty.
Reasons not to do this: some overlap of fields.
Reasons to do this: most processing involves just one or the other. Why have optional fields? Why waste space?
SQL UNION can be used when application calls for information from both tables.

8. SELECT UNION
SELECT column_name(s) FROM table_name1 UNION SELECT column_name(s) FROM table_name2
SELECT fname, start_date FROM faculty WHERE start_date < 2005 UNION adjname, start_date FROM adjuncts WHERE start_date < 2005
NOTE: the start_date expression may be wrong…

9. SELECT …. BETWEEN Can combine two tests using the BETWEEN operator
SELECT department, COUNT(*) as c FROM students GROUP BY department HAVING c BETWEEN 5 AND 10
SELECT department, COUNT(*) as c FROM students GROUP BY department HAVING c >= 5 AND c<=10.

10. SELECT … BETWEEN Assume table with fields that hold dates.
SELECT * FROM orders WHERE orderdate BETWEEN '7/20/08' AND '8/05/08';
Will this work for late July, early August? Need to research date and date/time 'arithmetic’.

11. Exercise/Classwork
Consider customers (cid, cname, zipcode), products (pid, pname, price), orders (oid,cid,date), orderedproducts (opid, oid, pid, quantity) example.
Generate list of zipcodes with total number of orders.
Generate list of product names, with total ordered for each zipcode
Generate list of customers who had orders made in the summer of ?
Can work in pairs. Turn in work.

12. Hints Decide on tables needed
Some fields in some tables, maybe even all the fields in some tables, may not be part of the result. They are needed to make up the JOINed table to obtain the results.
Generally, how tables are JOINed, the ON conditions is fixed
Decide on WHERE conditions . These are conditions on individual records.
Decide if any GROUP operations: any aggregations
NOTE: DISTINCT also does an aggregation
Decide if any HAVING conditions: conditions on aggregated results
Decide on any functions, e.g., COUNT(*)
SELECT zipcode, count(*) FROM customers as c JOIN orders as o ON c.cid = o.cid GROUP BY zipcode ORDER BY zipcode
SELECT p.pid, pname, zipcode, count(*)FROM customers as c JOIN orders as o ON c.cid = o.cid JOIN orderedproducts as x ON o.oid = x.oid JOIN products as p ON p.pid = x.pid GROUP BY p.pid, zipcode
SELECT DISTINCT cname FROM customers as c JOIN orders as o ON c.cid = o.cid WHERE o.date BETWEEN ‘ ’ AND ‘ ’

13. An example: citations
The citations system provides visualizations of how articles reference other articles. The “archivists” input journals, articles and links from original article to referenced article. The “viewers” request a visualization. Note: this can be a base project for enhancement.

15. ER Articles id title symbol journal Links id Original article
Referenced article Jo
Journals id
name …

16. Data flow diagram in words
Who are the agents?
Archivists (my term): those who put in the information (and potentially edit it, though I haven’t done that yet)
Viewers (my term): people looking at the links
What are the processes (aka task)?
Enter journals. Enter articles. Enter links.
View links
What are the data stores?
Journal table. Article table. Links table.

17. DFD Enter journals archivist Journal table Enter articles
Article table
Enter links
Links table
View links
viewer

18. Decisions
Visualization consists of nodes (rounded corners of different colors) and arrows.
Ask archivists to make up short (3 character) symbols for each article.
Have program assign colors to journals. The node color is the journal color.
Viewer can click on node for more information
Article title and journal name.

19. Programs
Go to Database projects and click on Journals, articles,… links

20. Reflection Very preliminary Such systems (probably) already exist
Want to add
Edit feature
Adjusting visualization by moving nodes
Data report: for example, number of in-links and out-links
Some action done client side, some server side
I had an arrow program from origami examples
Time to talk to my client (that is, my son)

21. Classwork / Homework
Form teams and decide on general idea and post proposal.
Prepare planning presentations for next class.