SQL Server 27 - How to Create FOREIGN KEY Constraints

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[Zetobis]

But SpeciesID is not a FOREIGN KEY in this example... (The FOREIGN KEY attribute is missing) ¿no?

[mariosconstantinou]

I have been trying for days to figure out why I couldn't assign a foreign key to my table. Turns out I had to create the parent table first and then assign the key to the second table. After all the research, books, videos, tutorials. No one mentioned that there needs to be an order of creating tables. You solved my problem in just 2 minutes and I cant thank you enough!

[Shiyounin]

You're the best, man. SO many little things you throw out there that make it all much easier to understand. I would not be able to make it through my classes without your videos.

[spacemeter]

Thanks, man!
I kept getting an error and I did not get why, but now I now that the attribute of the foreign key HAS TO BE UNIQUE!

Helped out a lot!

[abebayehumengesha]

How do you create foreign key constraints by it self not next to the specific column name ? Not like the way you did it now

[carsonbrooks]

Does the order of the tables created matter in a script? I want to reference other tables in the script that are only a few lines down, but I don't want to make an error.

[Shylo-Mylo]

WOW THANKYOU, literally no one else online explained it in a way I understood. I can hand in my assignment because of you.

[antivenom]

Is it possible to add more than one foreign keys in one cell??

For table of movie and genre.
A Movie may have more than one genre in it. So can we add 2 or more genre in a column from Genre table?

[jnmrgn]

This is by far the best and simplest explanation I have ever seen.

[MTBikeBo]

You Sir are Awesome!! I am new to SQL stuff. Your explanation are very clear. Thanks.

[emircankocatepe]

thanks for your explanation it is really helpful but i have a question. so what is the difference between running it with constraint ... foreign key... query? they do the same job.

[vramgb]

Do you do personal tutoring? Please im need of assistance with my college material. :-/

[AyarPortugal]

Your dog sneezing? that's him realizing you're not talking to him, he's not the center of the universe =O

[rifathossain]

SOMEONE HELP ME.... IT SAYS INVALID DATA TYPE
CREATE TABLE ORDERS
(
OR_ID NUMBER NOT NULL PRIMARY KEY,
C-ID NUMBER NOT NULL REFERENCE CUSTOMER(C_ID),
P_ID NUMBER NOT NULL REFERENCE PRODUCT(P_ID),
TRACK_NUM NUMBER NOT NULL,
ORDER_DATE DATE NOT NULL,
QUANTITY NUMBER NOT NULL,
SHIP_DATE DATE NOT NULL,
DELIVERY_DATE DATE NOT NULL,
PAY_TYPE VARCHAR2(4) NOT NULL
);

[kylehawk]

DROP TABLE IF EXISTS doesn't work

[anugupta]

still benefit your playlist 2024, can you make one more latest for sql server playlist

[ab_.]

If there’s a ducking tech nerd downstairs trying to get information you’re risking your life just letting you know

[cwtrain]

In the hierarchy of biological classification's eight major taxonomic ranks, species is literally as granular as you go. If you loaded up that table with several million animals like you said, every single species _would_ be unique by their binomial nomenclature.

I see what you're getting at, but the example's blatant gloss-over of high school biology lost me.