Database Lesson #2 of 8 - The Relational Model

Dr. Soper gives a lecture on the relational model and its role in the database world. Topics include relations, primary keys, composite keys, foreign keys, normal forms, and the normalization process.

[AlexandriaRohn]

00:19 Topic Objectives
01:37 Entity: represents a single theme or concept with which we want to track its attributes. e.g. department, employee, or project.
02:43 Relation: a relation is a type of table. Relation table characteristics: rows contain instances of a table, each column is an attribute, each column are of the same data type, each column has a unique name, cells of the table hold only a single value, no two rows can be identical, the order of the rows and column do not matter.
08:28 DB terminology synonyms: table = relation, row = record, column = field = attribute
09:40 A key is a column(s) of a relation whose values are used to identify a row
11:45 Topology of DB keys
12:09 Composite key: unique key, composed of two or more columns.
15:12 Candidate key: unique key, has potential to become primary key.
15:50 Primary key: unique key, main key for identifying a specific row in a table.
17:35 Surrogate key: unique key, added to a relation to act as the primary key.
19:20 Relationships between tables
19:30 Foreign key: non-unique, a foreign key is a primary key from one table placed into another table so that the tables can be linked
22:48 Referential integrity ensures foreign keys refer to actual entities in another table
25:30 Null value
30:32 Data normalization: process of analyzing a relation to ensure that it is well formed (i.e. not susceptible to anomalies)
37:02 First normal form: table contains no multivalued attributes. Every attribute value is atomic. Thus, all relations are in first normal form.
39:13 Second normal form: 1NF + every non-key attribute is fully functionally dependent on the entire primary key. i.e. we can't have partial dependencies among attributes of the table.
43:32 Third normal form: 2NF + no transitive dependencies

[trevorkubonga]

The best database course on YouTube. Well balanced and well explained.

[DaveDugganITPro]

these videos from Dr. Soper seem excellent to me. His tone and demeanor are relaxing and conducive to learning which I appreciate. No adds - he is not trying to sell something . thank you

[GGInfamous]

This IS the best video I've ever watched for a college class. You are explaining the whole chapter about relational models in depth without skipping over any information. I WISH you were my teacher.... Thank you for saving another student.

[ducayzane]

I've learned a lot from this lesson as well as L1 and willing to continue to learn until the end of this course. In the meantime, thanks to Dr Soper for this impressive free course of his.

[KB-vvgr]

These videos are how I'm passing my Data Management Foundations course at Western Governor's University

[maomaojin]

THANKS VERY MUCH!! I HAVE TAKEN 5 DATABASE LECTURES IN COLLEGE, AND I LEARNED NOTHING FROM MY PROFESSOR. YOUR LECTURE VEDIOS TAUGHT ME EVERYTHING!

[TheRealDougLane]

Very helpful, clear explanation of topics that confused and bored me to tears.  It still bores me, but at least I now understand it.  Thanks.

[omnidp]

By far the GREATEST lecture on the topic. He has such a deep understanding of the learning curve.

[mikealpha]

I am luck to watch your lectures as my first step into DB world. Thank You Sir.

[TheFrododk]

This is by far, the best introduction to Relational Database, I am reading these monster books about this subject and sometimes have to read it 3 or 4 times and still not fully understand some of it. But these lessons are great and understandable, So thanks a lot for your great work with this. :-)

[churchofmarcus]

I read two textbooks and couldn't learn this stuff. You are helping to make online school doable and in the process saving me thousands of dollars and hours of time. I thank you.

[davidlr]

this presenter is much clearer than a lot of actual uni lecturers...

[Thadnill]

These first two video parts summed up around 8 hours of lectures in school, and I learned even better from these two videos

[aditixchand]

This whole series is awesome. I have seen lessons 1, 2 and 4 and I feel very prepared for my DBMS exam. I feel like I understood the concepts so much better than what I have in a month in class.

[kaizhou]

Really great videos.
I'm a .NET developer with 4 years working experience, but still find your lectures very helpful. You helped me re-think and clarify many fundamental concepts.
Thank you Dr.   

[noahtaylor]

This is really really well taught. I am not a programmer nor do I have formal programming training, but I have a passion for it and my programs only depend on small data files like .jsons or .py files which are updated and their contents reimported to the program on its next instance. For someone without much experience, the thorough and concise way you explain things makes it very easy to follow and expand my knowledge really quickly. I cannot thank you enough for posting this lecture series.

[alec.]

the enthusiastic voice also helps shred some of my depression crumbs.

[marksmith]

Awesome, just awesome the way you explain it, so it can be understood and you give everyday examples.I've looked at video after video and finally found yours. I was struggling now I'm starting to get. And this is just the 2nd video. THANK YOU

[mypublic]

Simply superb. Highly appreciated. Full respect. I have learned a lot. Can't thank you enough Dr. Daniel Soper! My best regards.