Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
If the deletion violates referential integrity constraint, then three alternatives are available:
Example:
Let R:
A#
B
C^
A1
B1
C1
A2
B3
C3
A3
B4
A4
C5
Q
C#
D
D1
D2
D3
Note:
1) '#' shows the Primary key of a relation.
2) '^' shows the Foreign key of a relation.
(1) Delete a tuple with C# = 'C1' in Q.
Violated constraint: - Referential Integrity constraint
Motive: - Tuples in relation A refer to tuple in Q.
Dealing: - Options available are
1) Decline the deletion.
2) DBMS may automatically delete all tuples from relation S and Q with C
# = 'C1'. This is known as cascade detection.
3) The one more option would result in putting NULL value in R where C1 exist, which is the initial tuple R in the attribute C.
What is a virtual table that draws its data from the result of an SQL SELECT statement? View is a virtual table that draws its data from the result of an SQL SELECT statement.
Question: Describe briefly the three parts of the Relational Model. (a) The term integrity refers to the accuracy or correctness of the data in the database. Define the fol
# ???? ..
Code an Oracle Database trigger to enforce the constraint that an employee can never change his or her department.
Create a Student database and Retrieve the names of all students majoring in ‘CS' Consider the following relational database: STUDENT (name, student#, class, major) COURSE (co
Define query language? A query is a statement requesting the retrieval of information. The portion of DML that includes information retrieval is known as a query language.
Demonstrate the UML model Using UML, it is possible to generate code in any of the programming language from UML model (called forward engineering) and rebuild a model from an
What are the drawbacks of shadow-paging technique? The drawbacks of shadow paging is:- a) Commit Overhead b) Data fragmentation c) Garbage collection
Compare wait-die deadlock prevention scheme with wait-wound scheme Ans: Wait-Die Scheme a) Based upon a nonpreemptive technique. b) If Pi requests a resource present
What are the two types of indices? The two types of indices are:- A) Dense index B) Sparse index
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd