Self-join, Database Management System

Assignment Help:

Self-Join:  In a self join a table is joined with itself.  Let consider the following sample partial data of EMP table

EMPNO

ENAME

MGRID

.....

1

Nirmal

4

 

2

Kailash

4

 

3

Veena

1

 

4

Boss

NULL

 

.....

.....

...

 

Example: Search the name of each employee's manager name.

SELECT WORKER.ENAME || 'WORK FOR' || MANAGER.ENAME FROM EMP WORKER, EMP MANAGER

WHERE WORKER.MGR=MANAGER.EMPNO;

Output:

                                                                        2033_Self-Join.png


Related Discussions:- Self-join

Attributes, Attributes and its types explain?

Attributes and its types explain?

What is database files , The database files accept the actual data and ...

The database files accept the actual data and are typically the biggest in size. Depending on their shape, the tables for all the user operation can go in one database file-but

Draw and explain the three level architecture of database, Draw and explain...

Draw and explain the three level architecture of the database system? A DBMS gives three levels of data is said to follow three-level architecture. The trget of the three-schem

What is E-R model, E-R Model This data model is based on real world th...

E-R Model This data model is based on real world that consists of basic objects named entities and of relationship among these objects. Entities are illustrated in a database

Why does a dbms query language is designed, Why does a DBMS query language ...

Why does a DBMS query language is designed? A DBMS query language is designed to support end users who use English-like commands. support in the development of complex applicat

Which model is record based logical model, Which model is record based logi...

Which model is record based logical model? Network Modelis basically known as record based logical model.

What are composite objects, What are composite objects? Objects that ha...

What are composite objects? Objects that have other objects are known as complex objects or composite objects.

What is theta join explain, What is theta join explain? Theta  Join  -...

What is theta join explain? Theta  Join  - The  theta  join  operation  is  an  extension  to  the  natural-join operation which permits us to merge selection and a Cartesian

Data mining, 1.Why we need data mining? Give an example to illustrate your ...

1.Why we need data mining? Give an example to illustrate your answer. 2. Why data mining is considered as "misleading name"? 3. Distinguish the difference between database an

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd