1. http://www.cse.msu.edu/~cse103 U:/msu/course/cse/103 Day 07, Slide 1 Day 15 Review What datatype would be an appropriate choice for: –A cell phone number –A favorite color –A birthday or annivesary What was the primary key for tbl_People? Why? What did we do about missing data?

2. http://www.cse.msu.edu/~cse103 U:/msu/course/cse/103 Day 07, Slide 2 Day 16: Intermediate Design; Updating single-table designs What information in your contacts database is stored poorly? –Many of the records have NULL –Some records contain the same value Can we group some of this information together somehow? If we move data to another table, how do we relate it back to tbl_People?

3. http://www.cse.msu.edu/~cse103 U:/msu/course/cse/103 Day 07, Slide 3 Contacts Database The database contacts.mdb currently consists of a single table. We now need to accommodate a wide variety of email data –Some friends have school, work, personal accounts –Some family members don't have any email at all! How should we change the contacts database to best handle this new data? What type of relationship is needed? –Assume no one shares an e-mail address

4. http://www.cse.msu.edu/~cse103 U:/msu/course/cse/103 Day 07, Slide 4 Four Steps to Redesign the contacts database Design the new tbl_Emails table –Fields, Names, Datatypes –We will make the assumption that an email address can belong only to one person (without this assumption, we would need several extra steps) Transfer the existing data to the new table and CHECK YOUR RESULTS Delete the unneeded column(s) from the original table (But once they’re gone…) Enter any new email information

5. http://www.cse.msu.edu/~cse103 U:/msu/course/cse/103 Day 07, Slide 5 First Step Design the new tbl_Emails table –Fields, Names, Data types –Remember: This table is to describe the “Emails” entity, not People Information not related to an email address doesn't belong here! –What is an appropriate primary key? –What foreign key(s) might you need to use? When you make a new table, it should (almost always) have a foreign key from at least one other table

6. http://www.cse.msu.edu/~cse103 U:/msu/course/cse/103 Day 07, Slide 6 Next Steps Transfer the existing data to the new table using action queries –CHECK THE RESULTS!!! Delete the unneeded column(s) from the tbl_People table (AFTER checking) Enter any new phone information in the new table tbl_Phones

7. http://www.cse.msu.edu/~cse103 U:/msu/course/cse/103 Day 07, Slide 7 Redesign debrief What is the primary key in the new tbl_Phones table? Is there a foreign key in the tbl_Phones table? If so, what one? How was the data transferred? What column(s) needed to be removed? What difficulties were encountered?

8. http://www.cse.msu.edu/~cse103 U:/msu/course/cse/103 Day 07, Slide 8 Updating database exercise Note the size of your contacts database file now and again after these steps. Update the data type and length of each field in both tables to what is actually needed to accommodate the data. Use HELP to find out how to compact a database. Compact your contacts db. How was the size of your file affected?

9. http://www.cse.msu.edu/~cse103 U:/msu/course/cse/103 Day 07, Slide 9 musicDay07 database In classical music and jazz, many artists perform together on a single album but do not actually form a group. What type of relationship does this imply exists between artists and albums? How does our database musicDay07.mdb accommodate this? How can we change the database to handle this situation?

10. http://www.cse.msu.edu/~cse103 U:/msu/course/cse/103 Day 07, Slide 10 Four Steps to Redesign the musicDay07 database Make a new table tbl_PerformsIn Transfer the existing data into the new table and CHECK THE RESULTS Delete the redundant info from the original tables (AFTER checking) Enter any new data into the new table –This new data is in the Classical_Music07.xls file in today’s AFS space (see next slide)

11. http://www.cse.msu.edu/~cse103 U:/msu/course/cse/103 Day 07, Slide 11 Homework Work on the classical_music07.xls import –What problems do you run into? –How can you solve these? –If you can’t finish, come prepared to discuss your problems on Day 08. Check the link on today’s classwork page for homework to do for Day 08 –Transfer addresses like phones –Finish redesigns from class (Phones, PerformsIn)