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SQL tutorial 19: ON DELETE SET NULL clause of Foreign Key By Manish Sharma (RebellionRider)

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SQL Tutorial 19 : ON DELETE SET NULL foreign key Clause. Links used in the tutorial On delete set null website article [ download SQL script from same link] : http://www.rebellionrider.com/on-delete-set-null.htm Foreign Key Tutorial Video : http://youtu.be/0nbkBI5r3Gw Foreign Key Tutorial Blog : http://www.rebellionrider.com/sql-foreign-key.htm This video is the part of foreign key video In this sql tutorial you will learn the referential clause ON DELETE SET NULL of foreign key. On Delete Set null clause guarantee the relation integrity in foreign key/ Tool used in this tutorial is SQL Developer. This tutorial series is part of SQL expert exam certification training. if you are preparing for SQL certification you can use my tutorials. This SQL Tutorial is a part of free training. Copy Cloud referral link || Use this link to join copy cloud and get 20GB of free storage https://copy.com?r=j7eYO7 Contacts E-Mail [email protected] Twitter https://twitter.com/rebellionrider Instagram http://instagram.com/rebellionrider Facebook. https://www.facebook.com/imthebhardwaj Linkedin. http://in.linkedin.com/in/mannbhardwaj/ Thanks for liking, commenting, sharing and watching more of our videos This is Manish from RebellionRider.com
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Text Comments (24)
Puneeth Mohana (1 month ago)
I have added constraints in child table n I can see in GUI in constraint tab. But when I run query for ' user constraint' defined I get 0 value.
Sriram Torvi (2 months ago)
what if the child table column was set to not null?
GAVI GHUMMAN (1 year ago)
Your Voice reminds me of "FARHAN AKHTAR"
Babak Elikaee (1 year ago)
tnx Manish. you are doing great. I need to add a comment I think drop foreign key and re-create it missed. ALTER TABLE books DROP CONSTRAINT bok_col3_fk; -- drop foreign key ALTER TABLE books ADD CONSTRAINT bok_col3_fk FOREIGN KEY (book_author_id) REFERENCES authors(author_id) ON DELETE SET NULL;
Wenmei Ming (2 years ago)
Nice lectures. Appreciate your great work. Thanks, man.
Abhrajit Ghosh (2 years ago)
Qq. instead of dropping the table books, cant we just drop the foreign key constraint? And then add it back using alter table statement?
sir plese ap ap ke videohindi me upload karte to hindi ya gujrati media valo ko bhi acha hota
Prem Kumar Inti (2 years ago)
i should thank you for this video, i had a confusion about this constraint,,,,,,,,,,,,,,,,,,,,,but after watching this...........i clearly knew about this..............thank you manish
Nupur Singh (2 years ago)
Very good videos. Getting a thorough understanding of concepts. You should think of creating tutorial videos for websites like Udemy. Its just a suggestion as you will get wider student audience. Best Of luck!!
Bhasker Kaveti (2 years ago)
Hi Manish, Thanks for your tutorials. I have a question, why am i not able to see any data under user_constraints table, any idea. I created Child table under HR schema and when i run user_constraints no data is returned.
Source!!! (2 years ago)
Thanks for this tutorial Manish. I was wondering if you can set another value like Nil instead of Null when deleting a foreign key? The reason I ask is because in database at work, when I remove a relationship between some object tables, the business rule states that I need to remove the applicability of that object, where an applicability of that object can be more than 1 variable across multiple rows. In that situation where the primary key in a parent table existing in the children table more than once as shown by the multiple rows, is there a way to set the delete to Nil to change the objects applicability?
Jyotimoi das (2 years ago)
The video tutorials are great !!! Thanks a lot #Manish .!!!
Abdullah saad (3 years ago)
really good job and great job its help me a lot to learn SQL thank you very mush Mr.Manish
Manish Sharma (3 years ago)
+Abdullah saad Thank you for your appreciation. I am truly humbled by it. Keep sending your love and support it means a lot to me.
Sanoberjahan Ansari (3 years ago)
doing a god job ,really your videos are awesome !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! it helps me a lot to learn SQL .
Manish Sharma (3 years ago)
+Sanoberjahan Ansari Your comment has become the star comment of the day and is being featured on all my social media. Make sure to check it out. Twitter:https://twitter.com/RebellionRider Facebook Page:https://www.facebook.com/RebellionRider.officia Facebook Profile:https://www.facebook.com/imthebhardwaj Instagram: https://www.instagram.com/rebellionrider/
Manish Sharma (3 years ago)
+Sanoberjahan Ansari Lots of thanks for your appreciation. It means a lot and I will try to keep up the good works.
Fab TV (3 years ago)
Very good thanks
Mohammad Hannan (3 years ago)
really  nice and educational vedio.Many Many  thanks.I pray for you .
Manish Sharma (3 years ago)
+Mohammad Hannan Thanks, Your appreciations means a lot to me
Ashwin kumar singh (4 years ago)
hello manish, i am facing a problem in oracle 11g. whenever i am trying to connect https://localhost:1158/em, it gives me this Error code: ERR_CONNECTION_REFUSED. after installing the oracle 11g it worked fine. next day when i tried, i am getting this issue. please help me to fix this. thankyou in advance.
איציק א (4 years ago)
info s (4 years ago)
Diference Between & and && in SQL WITH example.
javed Ahmad rahimi (4 years ago)
when we use & only so run time we can give values number of times  but if you use  && so only for one time during  run time you  can give value  not  multiple time it is something like saving the value which you give  for first time .

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