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Thank you so much, so clear and so short-spoken, I mean you have pointed out only the necessary information, video is in normal length which doesn't tire the listener👍👍👍. 28.05.2023, 23:20
hey! very well explained... the main thing is....... voice is very clear as well as cute!.. aaur bhi video bna sakte ho .. column level and table level add karna chahiye tha kya ?
Primary key and unique keys(Entity constraints)def on table level or column level. Not null and Check (Domain constraints) only on column level. Foreign key (Referential constraint) define on table level as well as alter level.
Hi sis, your explination is crystal clear, very useful for me, i have one doubt foreign key means it is both not null and unique, In example while creating table u mentioned id not null and also primary key(id),what my doubt is primary key=not null+unique, why u specified again id not null, u already specified primary key primary key includes not null and unique that is my doubt sis, thank you
Hi, nice session. 1 query - you said primary key is combination of NOT NULL + UNIQUE. Then why do we have to explicitly define ID as NOT NULL. Shouldn't it be obviously when we specify ID as Primary Key?
Exactly this is what i was thinking at the time of session, why we need to add not null if we've mentioned primary key. May be she gave an example that we can add there also
@@Raj_chaurasiya305 bro Because I'd is Not Same Of anyone Just like your roll Number in school And also There Is no One Of the Student Have not a Roll no That's Why we Can apply Primary key On I'd column and Also If You want To apply only not null They It will be Okay But see Your roll No and another Student Roll No Inserted same In Table Then No Error will be there And Also Only you Apply Unique Constraint then It will Be okay But In I'd Column We don't Make it blank Because Every Student has his Unique I'd
You have to defined NOT NULL first if you want to add PRIMARY KEY constraint to a existing table, but if you are adding Primary Key constraint at the time of table creation then you dont have to defined NOT NULL, It will take it itself
Just Some Addition... Constraints can be divided into the following two types: 1. Column level constraints: Limits only column data. 2. Table level constraints: Limits whole table data. SQL Constraints are rules used to limit the type of data that can go into a table, to maintain the accuracy and integrity of the data inside table. NOT NULL UNIQUE PRIMARY KEY FOREIGN KEY CHECK DEFAULT Note: Constraints can be column level or table level. Column level constraints apply to a column, and table level constraints apply to the whole table. Hope this will help.. :) Good Job, Keep it up!!
Create the following tables with given attributes having appropriate data type and specify the necessary primary and foreign key constraints: Customer (Custid, Custname, Addr, phno,panno) Loan (Loanid, Amount, Interest, Custid) Account (Acctno, Accbal, Custid) a. Display the Account balance amount of a particular customer ARUN b. Update the interest with 1% when Accbal of the Custid >50% of Loan Amount c. Create a View with Accbal and Loan Amount of all Customers d. Create a trigger which checks for minimum balance in the account.
