Database Normalization in SQL - 1NF, 2NF, 3NF, 4NF - SQL Training Online

[@joeyblue1]

TABLE OF CONTENTS 00:00​ - Intro 01:07​ - 1st Normal Form 4:18​ - 2nd Normal Form 9:44​ - 3rd Normal Form 13:50​ - 4th Normal Form 17:33​ - Normalizing Customer Orders 20:35​ - Customer Table (2NF) 21:55​ - Product Table (2NF) 24:20​ - Order Header vs Order Lines 29:05​ - Product Table (3NF) 31:25​ - Customer Table (1NF, 4NF)

[@Kipviss]

nee.

[@hooo254]

@@Kipviss .

[@deepashankar08]

That's brilliant, confused by a textbook but fully normalised now!

[@organiz-izedtravis6411]

This video will top the search results in youtube on "DB Normalization" going forward.

[@4FrogsStacked]

Great explanation! It's obvious that you actually understand the topic well, and you're not just spewing out definitions. I've had some difficulty understanding these concepts until now

[@girls_game_as_well4397]

I have been struggling with this concept all week in class. I finally get it. Thank you so much.

[@MaxProskoff]

Thank you for explaining this so clearly. I like the focus and the delivery.

[@hectord.7107]

I'm a total noob on this topic and watched many videos about database normalization, this is the simplest explanation on the topic and the one that helped me the most improving my database structure. Thanks a lot!

[@harjos78]

Best explaination i have seen so far in any book or video!. Hats off. Great example and walk thourgh

[@montrealbudd2831]

I really like this video. It was so much easier for me to understand normal forms by watching this video instead of reading my book. Thank you so much!

[@alexandercato7400]

You did a great job teaching a complex topic in an understandable way! Just subscribed to your channel and expect you to get many more in the coming months because you’re producing quality content-it really stands out from the other videos on normalization. Keep up the great work!

[@chaslutterloh1309]

Thank you! This was an excellent format for a visual learner like me!

[@samiramir91samor78]

Thank you so much, you just make it easy for me to understand, that what a perfect teacher looks like.

[@vladyslavvlasenko4372]

Thanks a lot! Your explanation is absolutely easy to understand, examples are perfect.

[@richod9635]

Very well explained. This video tied up a loose ends for me. I already knew how to break apart one table into other tables, but this explanation really helped me to 100% confdent. Wouldn't it be a good idea to put 'Product Manufacturer Address' into it's own table in case the product is manufactured in multiple locations? If so, then what would be the key to the 'Product Manufacturer Address' table?

[@raytierney6342]

The absolute best !!!! Saving me from the land of total confusion!!!

[@KC-zn4gt]

Excellent video and clear explanation. Can't get better than this!

[@wanroslinawanmusa7532]

Thanks. Very easy to digest explanation on normalization.

[@skv4611]

Good explanation. After seeing the video, I felt like using pivot tables in Excel could speed up the process.

[@lokmanboukhoulda4496]

Thank you! the best explanation I have found on the net!!

[@fealgu100]

Simply great!

[@basharatmir4025]

Brilliant ,,,,,lecturer

[@chojuj4533]

Very well explained

[@EphemeralMemory]

Great, concise video! Thank you

[@shubhamsharma-ne2ke]

awesome video. Great explanation.

[@michalroesler]

Great video Joey.

[@helovesdata8483]

This is good. I'm new to this therefore, I'll need a week to design my first database...lol

[@mohammadkashkooly1987]

Joey, Thank you so much for helping us the little guys.

[@Hevletica]

I cannot thank you enough.

[@saltech2024]

Your tutorials are of no doubt .... Kindly make video(s) on "Entity Diagrams"

[@jkirkwold]

In the section explaining 2NF, when deduping the Product Table, you got rid of two rows. The first I understand (Bat, Louisville Slugger) because it was a duplicate. However, you also got rid of (Basketball, Titleist) even though it wasn't a duplicate. Why? Great video!

[@uzairkhan8953]

Really useful information. Helped me with my concepts. Thank you so much Joey.

[@dylang9790]

Thank you so much. your video is really useful for me

[@kishorearr6639]

love this one very much!!!!

[@jenh3183]

You're a great teacher - thanks for making this available to everyone.

[@johnsonmuppasani2208]

Excellent

[@htji4]

Thanks Joey, you're a great teacher.

[@AusieGamer834]

That's how you explain normalisation.

[@usmcpound]

Thanks so much for the informative video. This is much more clear and concise than the slides and book I've received from my database class.

[@blaze117]

In 8:30 your product table contains basketball-Spaulding basketball- titleist and ypu just deleted basketball titleist and the supplier titleist supplying basketballs suddenly disappeared from the database. im quite confused there

[@adityakolte2599]

Having 2 basketball products in Product Table would no longer keep the Primary Key Unique

[@nickbull7278]

@@adityakolte2599 But he loses information by doing so - how can you know that Titleist produces basketballs? This is a bad choice of primary key. Clearly other manufacturers can produce basketballs, and manufacturers can produce more than one product. The solution would be a new product ID column, or a composite primary key of both columns. Thinking forward, a product ID would be better, as the same manufacturer could make the same product, with additionally added columns for e.g., descriptions (e.g., different colors, sizes)

[@ReisQuarteu]

@@nickbull7278 The author corrected the above table in 8:36, so that basketballs are produced only by Spaulding in the simple example. That way, the 2NF was correctly applied. But you right: if two different manufactures can produce the same product, there was no dependency in the above table; therefore, the products table should not have been created.

[@Devruwan]

Great explanation of the topic. Thank you for teaching us :)

[@yahiabajbouj2818]

Thanks for this video

[@hamedahmadi1382]

thanks answered my question🙂

[@justinemsquare883]

nice tutorial

[@kanbisama]

Thank you so much for this video.

[@wehshijutt6537]

Excellent job

[@LenaDobrinova]

1. Thanks for your video! 2. One of the "Basketball-SP" records under the "Products" table needs to be deleted. 3. Price for "Basketball-SP" needs to be updated in the original table ( @16:49). It should be either $23 or $25. 4. Order Totals for "Customer Order ID" #1 and #4 don't look correct ("Customer Orders" table).

[@davidholguin6243]

That was Excellent ! I guess I’ve been lucky with not having so complicated data. Thanks, Sgt. Dave

[@johnesraelo4614]

excellent work Joey

[@IrishDean1000]

Thanks for this

[@mikesdailygaming]

Normalization might as well have been mandarin before now, thank you!

[@dawitworku821]

Thank you a lot, you are different!

[@Adeshiomedia]

waw impressive

[@ekaterinavolkova4348]

Great! Thanx!

[@dagmawihaddish3235]

Pls tutor java,c#,assembly. Only one ofcourse. I only saying this b/c u helped me a lot thank you very much.

[@ironicxd6994]

Thank you so much , this helped me a lot , keep it up plz

[@jbighitter]

Bob Smith on bottom two rows changes to Bill Smith later

[@michaelhunter4891]

Our teacher showed us this video.

[@umairjibran7]

those who haven't watched this video and searching for "DB Normalization" are even dumber than I am. This is a Life saver.

[@arnabpersonal6729]

Maybe youtube is

[@kaedien]

At 8:25, when normalizing to 2NF, Mark Smith has a Titleist basketball and Bob Smith has a Spaulding basketball. A few seconds later after deleting rows from the Product table, Mark Smith has a Spaulding (note: no longer Titleist) basketball. Manufacturer:Product was m:1 and then changed to 1:1 behind the scenes. This is confusing for those learning about normalization. It seems the error was noticed while recording and fixed "off camera" - it would be helpful to correct the error in the video for those of us following along. I was confused about how having just the product name as a foreign key could uniquely identify both the product and manufacturer when, at that point, two manufacturers had basketballs.

[@Kipviss]

niemand gaat dit lezen broer

[@kaedien]

@@Kipviss behalve jou!

[@GregoryKodolanyiRitter]

Great, thank you!

[@GoodDeedsLeadTo]

2nd Normal form Why do we need order date to make a unique composite key, when customer and product are sufficient to make a primary key? Please answer the question, thanks

[@fatefulwall3010]

Extremely helpful! Thank you Joey!!!

[@dosdeviant]

Glad I found this.

[@user-jz9rm8xn9n]

ذاكر الكويز يابطل…

[@brb2010ful]

قاعدين نذاكر

[@alemtewodros2131]

I am the luckiest to be here.Thanks Sir

[@adityagorre]

In this video 20:16 how did you sort product key. if we double click on that will it save all the rows

[@HerePiggyPiggy]

Your 2nd normal form needs composite keys for customer and product. Your “primary keys” fall apart the moment you get two customers with the same name or two basketballs from different manufacturers.

[@renaissongsman]

Keep watching? That happened after about 20:00 ... but, yeah.

[@kaedien]

This was fixed behind the scenes at 8:25. The Titleist basketball was deleted and Mark Smith's order was changed from Titleist to Spaulding.

[@marko-lazic]

But how are Dozen, Pack, Inch and $ atomic when they are combined with numbers?

[@markbrad123]

"Nothing but the key" An approximation of Codd's definition of 3NF, paralleling the traditional pledge to give true evidence in a court of law, was given by Bill Kent: "[every] non-key [attribute] must provide a fact about the key, the whole key, and nothing but the key".[7] A common variation supplements this definition with the oath: "so help me Codd".[8] Requiring existence of "the key" ensures that the table is in 1NF; requiring that non-key attributes be dependent on "the whole key" ensures 2NF; further requiring that non-key attributes be dependent on "nothing but the key" ensures 3NF. While this phrase is a useful mnemonic, the fact that it only mentions a single key means it defines some necessary but not sufficient conditions to satisfy the 2nd and 3rd normal forms. Both 2NF and 3NF are concerned equally with all candidate keys of a table and not just any one key.

[@brenthalbach3645]

Great stuff. How would you deal with price changes over time? Do you need a separate Price table with dates or something? Would be great to get your input. Thanks, appreciate your content.

[@helheimrgaming2547]

Thank you Joey, very helpful!

[@ronyniv22]

The best one that i have seen!!

[@happyjays7145]

I noticed that Product ID - Basketball - SP is duplicate in product tabke so it is not qualified as Primary Key...?

[@Martin-lf9se]

Nicely done Joey! Thank you...

[@perkjr7834]

How does product manufacturer depend on product if there is a manufacturer that has 2 diff products

[@NoWhiteGullibility]

Awesome

[@jeetsoni672]

hows does the qualntity depend on the order date? Can we just notpull the quantities using customer id and product?

[@osmankhaled4565]

Excellent Video.

[@Mind_Worm]

THANK YOU this helped so much!

[@kanduriveeresh9568]

It was very well explained with example, thank you

[@sukanyachauhan9653]

Joey, please help with the download link for SQL server. I am starting SQL learning from your video.

[@nickt423]

@26:24 You have the OrderTotal for OrderID 1 as $70 (in the Customer Orders table) but didn't bsmith1 order two $70 products. Shouldn't the OrderTotal for OrderID 1(in the Customer Orders table) be $140?

[@dafuq3122]

same questions

[@sulemanmasood1382]

sir my db is in mysql using MYISAM.... No foreign keys implemented with some columns repeating in tables as well... i have approximatelly 40 tables and all containns approx 500 rows.... but 5 or 6 tables contains above one million rows each....db is not normalized.....but it is still working fine...on LAN and on cloud as well ... what will be fuiture of my db...

[@shaidoeseverything]

Great video, Thanks!

[@giorgiodealcantara8374]

Thanks for the video, Joey! Pretty good explanation. I got with one doubt in the end. What is the PK for the Customer mail catalog and the customer email subscription tables?

[@stevenchen807]

Hi Joey, Thanks for the very instructional video. I do have a question. What do we do with the two ProductID Basketball-SP with different prices?

[@steeleye2000]

I think that was an oversight. They should either be the same price and then one of the rows would be deleted or the basketballs should be named to differentiate them (in the product column) like Basketball-yellow and Basketball-Orange.

[@edgarsvilums1550]

You just add a different Product ID for the differently priced one.

[@LenaDobrinova]

one of 2 records needs to be deleted

[@nolanhartwick4862]

This video is quite good. It would be great if you could keep doing more of these Database theory videos.

[@shingtome2179]

Thanks for the video!

[@jetmartin9501]

Great stuff! Very helpful. Not to be picky but in trying to understand the "solution" I noticed (in the original large table) that Bob Smith made two purchases on 8/9 and the Order Total didn't add up to the total of the two lines. The total in the chart is $70...shouldn't it be $60 or am I missing something? Also should the "Customer Email Subscriptions" and "Customer Mail Catalogs" tables be JOIN tables? It seems that there is a Many-to-Many relationship between these tables and Customers (e.g.,, Customers can subscribe to Many Email subscriptions and an Email subscription can belong to many Customers). Seems like the classic situation for a Join table. Also currently the way you have it defined there is no primary key for these Email and Mail tables (as there are duplicates). Not sure if that is an issue. Thoughts?

[@chriskobee356]

From 33:00 min to 34:30: why didn't you create a many-to-'many relationship between "Customer" and for example a table "Email-subscription". Now it looks like you created the intermediate table "Customer Email Subscription" but left out the other side (table Email subscription) that holds all the different types of subscriptions. Idem dito for the Mail Catalog set up.

[@aroxing]

Assume you have a table User(id, email, username). All fields are unique. Does it satisfy 3NF?

[@ruixue6955]

4:19 2nd normal form 5:05 *partial dependence* 6:55 resolve partial dependency 9:45 3rd normal form 11:46 transitive dependency 13:51 fourth normal form 17:12 demo example 17:34 1.

[@nyanyaa8043]

Hi Joey, Do you offer training beside the online videos? you are good at this.

[@rayhanrana6773]

Just awesome man!!!

[@BijouBakson]

Thank you, that was helpful

[@AggTheMag]

which application are you using for this lesson?

[@prasanthrajappan4401]

Do we need to split the Customer address in example 1 to make it in 1st normal form as address seems to be composite attribute?

[@vesselofrecovery]

You’re amazing!

[@sheripharedwards414]

so how you create in in sql .?

[@gooon666]

Isn't the Order Total field a Calculated field? Can it have a place in a table? If yes, how was it calculated here to show the results it exhibits here? Newbie here, thank you :)