MySQL: ON DELETE

#MySQL #tutorial #course

00:00:00 intro
00:02:24 SET NULL
00:04:40 CASCADE
00:07:11 conclusion

ALTER TABLE transactions
ADD CONSTRAINT fk_customer_id
FOREIGN KEY (customer_id) REFERENCES customers(customer_id)
ON DELETE SET NULL;

ALTER TABLE transactions
ADD CONSTRAINT fk_customer_id
FOREIGN KEY (customer_id) REFERENCES customers(customer_id)
ON DELETE CASCADE;

[BroCodez]

ALTER TABLE transactions
ADD CONSTRAINT fk_customer_id
FOREIGN KEY (customer_id) REFERENCES customers(customer_id)
ON DELETE SET NULL;

ALTER TABLE transactions
ADD CONSTRAINT fk_customer_id
FOREIGN KEY (customer_id) REFERENCES customers(customer_id)
ON DELETE CASCADE;

[contactdi]

Bro you made everything so easy peasy to understand. Love you

[massivestrokeee_]

thank you for you incredible work bro i luv u

[navidrahbar-musicproducers]

I love how you explain things in the simplest way.
Perfectly understandable.
Many thanks man.

[BenisNostalgic]

Hey Bro, could you please create java spring boot tutorial.

[acminostgien]

question, if the data that has the foreign key is not nullable, does the on delete set null still work?

[nicolewynne]

could you please do full PHP course bro?

[_sumedh_music]

Hi bro, I am following your whole SQL series and I have learnt all the concepts but this ON DELETE concept sucks. I typed the same query as you have shown but still it gives me error "Error Code: 1451. Cannot delete or update a parent row: a foreign key constraint fails (`mydb`.`transactions`, CONSTRAINT `transactions_ibfk_1` FOREIGN KEY (`c_id`) REFERENCES `customers` (`c_id`))". Can you please help me with this @BroCode .

[funnyoceanofmemes]

i dont know bro what is your obsession with poppy puff