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.
I need a professional to prepare a database to collect and store basic information. The information can be basic info such as contact details etc. One requirement i have is f
What is Interaction Diagram An interaction diagram shows an interaction, comprises of a set of objects and their relationships including the messages that may be dispatched be
Define entity integrity and referential integrity. How does SQL allow specification of these? Ans: Entity Integrity Rule- If the attribute A of relation R is a prime attribut
Explain Two phase locking protocol A transaction is consider as to follow the two-phase locking protocol if all locking operations precede the first unlock operation in the tra
Determine the Strong and Weak Entity Based on the method of foreign key, there might be arise a situation when we have to relate an entity having a primary key of its own and a
What are the disadvantages of relational data ? Disadvantages • Performance - If the number of tables among that relationships to be established are large and the tables t
SELECT Statement This statement is used for retrieving information from the databases. It can be coupled with many clauses. Let us talk about these clauses in more detail:
Consider the entity type dependent related to employee entity, which is used to keep track of the dependents of every employee. The attributes of dependents are: name, sex, birth d
What is the use of unique function? UNIQUE function: If UNIQUE is specified then only unique values are used to computed the mean.
discuss the array implementation of a stack.
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