Database Lesson #4 of 8 - Data Modeling and the ER Model

[@ziadcs5309]

Dear Dr Daniel I just wanted you to know That I am a computer science student who lives in Syria With very Poor financial conditions so I cannot afford for private tutors to teach me dbms I'm so grateful for the high quality knowledge you provide here for free Words cannot describe how thankful I am Wish you all the best

[@dgenerationbigestfan]

please keep us updated on your progress. Us here are interested in how you end up!!!

[@ziadcs5309]

I appreciate your kindness, the situation here is very bad in all aspects, unfortunately I'm just doing the bare minimum to pass my courses at university, the electricity here is available only 3/24 (three hours a day at its best), I think I'm graduating next year, but I think its hard for me to get to the real job market, I may start learning web development (in case things does not go worse!!). thanks for your comment again it made my day, wish you a nice day @@dgenerationbigestfan

[@mgray999]

You're better than my prof. I've been anxious about this class because the lectures cover just spouts of info and not the details. Thanks for this!

[@Blue4736.]

Requirements to ER model 5:15 Entity class v entity instance 6:50 Entity class v entity instance visual 10:30 Attributes 11:20 Identifiers [keys] 13:10 Types of keys 13:50 Level of entity attribute display 16:45 Relationships 18:50 Conceptual unary relationship 21:20 Conceptual binary relationship Conceptual ternary relationship One or many connections 23:12 One-to-one binary relationship 24:10 One-to-many binary relationship 25:00 Conceptual many to many binary relationship Note: can’t build a direct conceptual many to many in a db. Need a middle table….extra entity 25:40 Conceptual many to many binary relationship/ extra entity 26:50 Maximum cardinality 27:20 Minimum cardinality 28:40 Crows foot symbols 29:20 Cardinality example 33:20 Er diagrams 34:40 Has -a-relationship 36:00 Strong and weak entities 36:30 Id-dependent weak entities 38:00 Weak entity relationships 40:00 Weak entity identifier/ non-id dependent 41:30 42:10 Subtype entities 44:00 Subtype entity identifiers 47:30 Subtype entity examples Recursive relationship 53:00

[@joannaglasby2596]

Hero status unlocked!

[@MelancholyMadoka]

You dropped this crown, @Warren L.

[@SRHarkreader]

Thank you so much Dr Soper; this is hands down, the best ERD tutorial I've ever watched. Great job!

[@sabanaar]

Thanks a lot Dr. Soper, best coverage on the data modeling and the entity-relationship (ER) model I have ever seen. You are one of the best teacher I have ever had.

[@GameFraper]

Paying 9 grand for uni and get a useless pdf as a resource. Pay nothing for an hour long, detailed, easy to understand video. This is just so wrong

[@ervincasiguran]

i feel you

[@BraulioCespedesAcosta]

Fedil Al-Hayawi That's the new model of education. The same thing happened to me. I got a book of data base design from the library, Too complex for a beginner, but this video make thing easier.

[@meyerjohannes]

+Fedil Al-Hayawi It's a f***ing scam. I decided not to buy any textbooks this semester (except for one that I found an older edition for $5). It's so frustrating, they release new editions every couple years, and the only thing that changes is maybe the introduction and the end-of-chapter questions! And then when you finish the course, a $250 book is suddenly worth $60. Better to rent, but it's still a rip off. About to graduate, and the whole time I'm thinking when I walk the dean is going to hand me a paper, saying "here's your receipt".

[@vayunandu]

well said!

[@promisennanemere4]

I understand you bro. It can be that bad.

[@ginaonline83]

I've taken 2 database classes in the past but I've learned so much from your series of videos than I've learned in the classes, very detailed and easy to understand, thx u so much.

[@oreed]

Dr. Soper, you are a great teacher. The content is so clear and easy to understand, the way you explain things is so logical, and your examples really help. Thank you for this!

[@prfgee8788]

Your method of presentation is second to none and your explanation is top notch. You deserve an award. Thank you!

[@bindenlibejohn7378]

If it must be done, It must be done well. Dr. you did it all . from simplicity through clarity to comprehensiveness. Bravoo!!!!!

[@jephthah2347]

This is the best tutorial on this topic you'll find on the internet

[@lilitanikushkina1194]

Love everything about your lectures - the pace, the material, the structure, presentation and also the manner of speaking. Huge thanks!

[@hkrumble]

Dr. Daniel Soper, thank you so much for this. This is by far the most clear, lucid explanation of data modeling and ERDs I've come across. Fantastic!

[@jimb6554]

At 20:56 I was having difficulty with the Person entity relating to itself with marriage. I was thinking “Aren’t 2 different entities getting married?”. Then I resolved the difficulty by realizing that A person entity is a table. While an employee table relating to a parking table is a binary relationship because it involves two tables, one person instance getting married to another person instance is a Unary relationship because it involves just one table which is why we also call it a reflexive relationship.

[@hauteswan2541]

This is a great addition to my non-lecture database class. I will recommend it to my class. Thank you.

[@streetdogg4406]

Kimberly wow. How easy is it being a teacher?

[@tiyezx5993]

Just came across your tutorials today after years of many challenges learning databases. I'll return to give feedback. Very positive comments so far about your work. Thank you

[@pajhume]

Very clear and concise. Video elaborates on specific details that are critical to understanding the subject matter. A+ quality. Deeply appreciative of your generosity!!!

[@christopheropara6083]

I thank God for creating people like you.

[@scienceklinic4584]

Saved the video in 2018 and watching in 2022. What a gem! Thank you so much, prof.

[@SrkySrky]

This is gold. The best lessons on KZbin.

[@agofpos]

37:07 "Any entity that is not a weak entity is called a strong entity" Very helpful.

[@jimc1499]

Dr. Soper thank you for this great video series.

[@binti3881]

this is the best video on Data Modeling . very clear and explanatory. well done prof.

[@fred.chapman]

*DR. SOPER* , I am learning a great deal from your lectures! I believe I found a small mistake at 52:52 and 55:03. In the recursive (unary) relationship between employees and managers, an employee need not have a manager (e.g., the CEO has no manager), but each manager must supervise at least one employee _and may supervise many employees._ So, the crow's foot symbol next to the employeeId attribute should have a cardinality of *one-to-many* , not one-and-only-one. Is that correct? Thank you!

[@GlebLobanov]

I have the same question.

[@thomasjust2663]

Who asked you id_ot

[@fred.chapman]

@@thomasjust2663, if another person's intelligence, knowledge, and ability make you feel so threatened, inadequate, and inferior that you become rude and insulting and lash out for no reason, then you have a real problem. You need to get help with that. I want you to talk with someone you trust, like a close friend, counselor, or therapist, to figure out why you are so desperately unhappy. You'll never find happiness by trying to tear other people down. You need to believe in yourself, invest in yourself, and build yourself up. I did it, and you can do it too. Will you try, Thomas?

[@junaidmughal3806]

I think you are right

[@radocisar3420]

p 9

[@vbossbla532]

Excellent explanations. Clear and concise. Thank you!

[@pikkosaksa]

a joy to refresh and learn with Dr. Soper. Thank you!

[@karnabudhathoki5311]

I have no formal training on IT.yet these lectures give me an insight into the IT world...Thanks...from Nepal.I am learning a lot...

[@tvd1826]

Thank you Dr. Soper for this presentation. It has been a great help!

[@scottmacnevin3555]

You have a teaching gift - like many others who have furnished a response - I currently study this topic at University. The teaching at my facility just isn't up to this standard when it comes to imparting concepts this clearly...I am almost at the end of your fourth video and feel I have such a good grasp of the concepts involved. Thank you

[@vbreddy800]

That is is great lecture I ever had before. Thanks very much Dr. Soper.

[@GSoftagon]

Dr. Soper, this is excellent. Thank you very much.

[@JFrameMan]

Very smooth and understandable explanation. Thanks a lot.

[@jim-ngormohkamara4805]

Dr. Soper you are a life saver

[@neetuarya2252]

Thanks a lot Dr. For this really informative lecture. Have a good day

[@kanchapagimhara584]

Great,perfect explanation.One of the best video tutorial in the youtube I have seen,I improved my Englilsh also as an extra benefit.

[@madiyarabdukhashimov8570]

I have studied all those things at the university and I had no idea what the heck I was studying. I could barely get B0 (B-) for all preparing tests and exams with many not sleeping nights. I was just happy not to get FAIL. I have been watching this video with 1.5X speed and can't believe everything is so well explained and easy to understand!)

[@manhungchan5447]

Well done, Dr. Daniel Soper.

[@fksheke1]

Thank you Dr Soper. This is really amazing. God bless you.

[@bedbathorybeyond]

I am very stoked on these videos.

[@caseyobrien1082]

Why hasn't my prof done anything like this? I'm having to scour the internet to find a lecture on the subject. My professor just has us read the book, then gives us assignments. He offers no other learning resources whatsoever. Thankfully I've found this.

[@GloriaCopeland563537]

Same here

[@bhatz829]

My professor doesn't even speak to me. Been asking about what I should do. I get this video. This isn't even on the chapter I am learning.

[@noniboi1673]

My lecturer just gave us a pdf, which were slides from THIS series. huehuehe

[@geetatiku]

Very useful.. Explaining it in a very simple way.. Thank You Dr. Soper.

[@nandhi19]

Valuable learnings keep life FRESH😊 Thank you for your valuable lessons🙏

[@kaizhou8278]

Thank you so much Dr. Daniel Soper.

[@VinaySesham]

Excellent. Explanation is so simple and effective.

[@xolelamqikela4534]

Writing business systems and analysis test in 12hours, thanks to Doc im gonna nail it

[@anvikshadixit4674]

Very informative lecture . i was able to understand the data modelling in much better way. Thank you sooo much for making such a great video with great explanation. :)

[@bettyseyfu8140]

Thank you so much Dr.Daniel Soper, this is the best use full and understanding lecture I never had i'm thank full! if you have more continuing database lesson 9 Ext

[@_devParty]

Thank you Sir. This is still relevant and informative in 2019

[@nareshpuppala1544]

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[@chaitanyavs]

Thank you for this amazing lecture series! One feedback- I'd love to see more examples of how to read the diagrams depicting entity relationships- You explained the concept well but some more examples would help the viewers

[@gramirom]

Amazing series Daniel! Thank you very much

[@M00nShad00w]

Thanks god for a video in KZbin I can understand

[@BobTheBob647]

Thank you for these videos, they have been incredibly helpful.

[@sohaibkhan8835]

Thank you so much Dr. Soper!

[@fmartinez004]

I took introduction to Oracle SQL and this is bringing it all together for me.

[@ajharrisTX]

Great presentation; well-spoken and thoroughly informative. Will definitely utilize your videos to supplement my AIS course!

[@aaronsalifukoroma7994]

I appreciate your careful systemic explanation

[@srv14evr]

You are an awesome teacher!

[@vadanmehta784]

Dr Soper.. thank you very much for knowledge.. u made things so simple ..wow :)

[@Cswaleomatic]

Thanks a Million Professor!!!! God bless you.

[@parthpatel4221]

very very useful, and easy to understand and in easy language. thanks

[@emperoy8]

Great man done great Job. Thanks Dr. Soper

[@csanadkozma7538]

Awesome vid! Now I understand the giant 20-30 entity diagrams in my work.now All I have to do is memorise them!

[@kevinpaul3285]

Great work on the video series. Very informative.

[@BrokkoliSchleuder]

wow, in this way (and length) every youtube video lesson should be. Nice!

[@2002egncn]

Awesome series. Thanks so much!

[@samanthapikus3178]

Thank you so so so much!!! My textbook is written poorly. Also, I now even understand objects and classes better. Thanks!!!

[@fatossm]

harika bir şekilde örneklerle küçük adımlarla anlatıyorsunuz, teşekkürler.

[@rotopercutorash]

very nice video! thank you for taking the time to share your knowledge. However, I had to speed up to 1.5 as i found it to slow but that is probably because i had too much coffee. Works like a charm

[@theamazingspiderplan]

Thank you Dr. Soper!

[@deepakpathak9368]

Great Videos and Very informative for building good concepts. Thanks.

[@delroyfrancis4491]

Thanks for all you do;

[@medbee6067]

very well explained Data Modelling and Entity Relationship Model. Thank you

[@harryk1317]

Thanks for the excellent presentation!

[@tamimhekmatpey2729]

Very helpful teaching presentation, above all I admire your good intention for sharing it with the public. Is there any other subjects or topics on your agenda? - Thank you.

[@zzhao463]

Question: If the PK of the strong entity is not a FK in the weak entity, and all other restrictions remains the same, would it be a non-id-dependent relationship?

[@ubongessien4934]

Thank you for this presentation, this was very helpful.

[@abv250]

Thanks very much for your lecture. I was able to connect a lot of dots. Would you post the slides - the examples help when trying to model parallet db schemas in my own work. Thanks again.

[@ivyma8593]

26:43 why do we must have third table link those two together?

[@ivyma8593]

can't it just be item-supplier

[@srest0173]

For the model you showed with undergraduates and graduates, how would you prevent losing the data about a student who goes from undergrad to graduate considering each one has their own specific attributes?

[@agofpos]

25:33 misleading picture, it should be Department -> Employee and not the other way around.

[@sywanneto1506]

The example of ID-Dependent and non-ID-Dependent weak entities gived by dr. Daniel had the same parent entity and almost the same child entity. The only difference was the way the parent's primary key was organized in the child entity (as foreign or primary ). Is the non-ID-Dependent and ID-Dependent choice arbitrary? I mean, are they only paradigm? or there's a best practices preferential onle? or depends of the case? Cause the example gave the impression that it doesn't.

[@BraulioCespedesAcosta]

Thanks, Professor.

[@sangminpark2948]

can an entity have more than 1 primary key? 43:27

[@zegeyewoldemariam9518]

that's really amazing God bless you

[@Cashman9111]

why do you have to acknowledge recursive relationship ? empId implies managerId so why does it have to be marked ?

[@0xatul]

Great Lecture

[@weiniu5400]

Very helpful! Thanks a lot for sharing!

[@autumnking100]

Thank you. Very well explained.

[@Karmidzhanov92]

For the last example, the diagram reads that an employ can have ZERO OR ONE manager (with which I agree) but a manager can have EXACTLY ONE employee (showed with the two hash marks) which the following illustration clearly proves wrong (as a manager had three employees under him) Did I miss something?

[@Karmidzhanov92]

Well asking the question I think I answered myself - managerId can be NULL, but a managerId HAS TO be one and only one employeeId

[@BattleFieldAllHands2022]

Can you provide the slides for your lecture?

[@Steve-zz5ds]

This series was highly recommended to supplement my DBMS course....but that microphone static in this video is incredibly distracting.

[@ayca7401]

great explanation!

[@NwankamaNwankama]

Excellent presentation

[@ianlee9505]

are these slideshows available anywhere for download?

[@nickwoodward819]

Are the 'Hiking_Club'/'Sailing_Club' types poorly named? A club surely isn't a subtype. Wouldn't they be better as 'Hiking_Student' etc? I know I'm likely splitting hairs, but it helps me understand the concepts.

[@nickwoodward819]

Great videos by the way, really helpful, although even in 2013 your microphone should be illegal :D

[@dudet15951]

Great videos!

[@popularcomments3272]

thank you dr for this amazing content

[@Regalert]

The guy is great!

[@silmankhan5832]

thank you very much !! very clear tutorial

[@TheAsimjan]

Thumbs up for u Sir. From where can I download these slides? If anyone knows please tell me as soon as possible