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.
(1) Insert into PERSON Violated constraint: - Key constraint Reason: - Primary key 1 already exists in PERSON. Dealing: - DBMS could ask the user to provide valid PER
Submit SQL SELECT Statements to demonstrate several reports off your database, according to the following guidelines: You must submit at least 5 SELECT Statements. Each
What is use of generating such tables? How can you create temporary tables? When you require a table only for a short time after that you want it to disappear automatically you
#questiontypes of keys examples..
discuss the purpose of the concurrency control?
What is OMR? OMR (Optical Mark Recognition) is the translation of marks - or the absence of marks - but not the shape of the mark on forms that have small circles ("also called
Exclusive lock It is asked for by a transaction on a data item that it wants to update. No other transaction can put either a shared lock or an exclusive lock on a dat
Eliminate Repeating Groups The problem is, "Find out the list of employees, who knows DB2". For this problem we require to perform an awkward scan of the list looking for re
what is inverted and multilist structure
What is a data dictionary? A data dictionary is a data structure which keeps Meta data about the structure of the database i.e. the schema of the database.
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