In Session 3 we learned about relational databases. We learned a bit of SQL and how to query databases. At first glance this was a bit difficult. The idea of tables and linking them together made sense because I have worked with MS Access before. I built a database for OACF's membership records. However, after this brief introduction to SQL and Databases, I'm sure that it could have been built in a much more effective way. What I learned from the lecture materials is that you can't take the spreadsheet mentality into the database word. Spreadsheet mentality makes you want to add more and more columns (which in database world represent entities or things) to the end of the spreadsheet if you need to account for more data. However, in databases, you need to create a new table for each new entity. That way it's easier to make changes to one table and link it to another table as opposed to changing all the records in one gigantic table.
After I understood that in order to query a database, you need to understand the tables and their attributes, it was fairly easy to get through. I did have some questions along the way, however, I finished the assignment in class. The toughest ones where the tables that had to be joined and I was unable to figure out how to join the three tables on my own. I just went back through and read the lecture notes and tried the exercises again. It went much faster this time although I did complete tasks 9 and 10 as my attention span started to wane. In fact, after I finish this blog post, I'm going to take a break. Anyhow, I've found that it's much more beneficial to my learning and application in the lab if I've read the lecture notes before class! I will be doing that from now on!
No comments:
Post a Comment