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!
Consider the relation PERSON. If you want to display details of persons having age less than or equal to 30 than the select operation will be used as follows:
σ AGE <=30 (PERSON)
The resultant relation will be as shown:
PERSON_ID
NAME
AGE
ADDRESS
2
Sharad Gupta
30
Pocket 2, Mayur
Vihar.
Note:
1) Select operation is commutative; i.e.,
σ (σ (R)) = σ (σ (R))
Therefore, series of select can be applied in any order
2) More than one condition can be applied using Boolean operators OR & AND etc.
Question : (a) Differentiate between database integrity and database security (b) Database security involves measures to avoid loss of privacy and loss of confidentiality. D
One-to-many : An entity in A is related with any number of entities in B. An entity in B is related with at the most one entity in A. Example: Relationship between faculty and d
Identify the need and use of data control through problem solving, illustration
Atomicity: It describes a transaction to be a one unit of processing. We can also say either a transaction will be finished completely or not at all. In the transaction example 1
Though all the ABAP/4 Dictionary Structures that exists in the structure of the LDB, being described in Database Program, we are explaining the Dictionary Structures in the Report.
Group By clauses • It is used to group database tuples on the basis of definite common attribute value like as employees of a department. WHERE clause still can be used
Waterfall model is the linear model. The process is completed by step by step. We couldn't stop in between of the process. Prototype model: after get the model by low cost budget o
List the drawbacks of relational database system A) Repetition of data B) Inability to s certain information.
Explain the Natural join Natural join is a binary operator which is written as (R* S) in which R and S are relations. The effect of the natural join is the set of all combinati
Describes the several relationship constraints through giving suitable example? Constraints on relationships: There are two kinds of constraints on relationships. 1) Mapping
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