Execute sql queries, Database Management System

Assignment Help:

Consider the relations described below:
PHYSICIAN (regno, name, telno, city)
PATIENT (pname, street, city)
VISIT (pname, regno, date_of_visit, fee)
Where the regno and pname identify the physician and the patient uniquely corresponding. Express queries (i) to (iii) in SQL.
(i) Get the name and regno of physicians who are in Delhi.
(ii) Find out the name and city of patient(s) who visited a physician on 31 August 2004.
(iii) Get the name of the physician and the total number of patients who have visited her.
(iv) What does the subsequent SQL query answer
SELECT DISTINCT name
FROM PHYSICIAN P
WHERE NOT EXISTS
( SELECT *
FROM VISIT
WHERE regno = p.regno )

(i) Select name, regno from PHYSICIAN where city = ‘Delhi';
(ii) Select pname, city from PATIENT,VISIT where PATIENT.pname=VISIT.pname and date_of_visit = '31-Aug-04';
(iii) select name, count(*) from PHYSICIAN, VISIT where PHYSICIAN.regno = VISIT.regno group by Physician . regno;
(iv) This will provide the name of physicians who have not visited any patient.


Related Discussions:- Execute sql queries

Data model, data models are being replaced over years. Reasons and why does...

data models are being replaced over years. Reasons and why does that happen?

Define seek time, Define seek time. The time for repositioning the arm ...

Define seek time. The time for repositioning the arm is known as the seek time and it enhances with the distance that the arm is known as the seek time.

What do you mean by correlated subquery, What do you mean by Correlated sub...

What do you mean by Correlated subquery? Subqueries, or nested queries, are used to bring back a set of rows to be used by the parent query. Depending on how the subquery is writ

Sparse and dense indexes, Sparse and Dense Indexes These indexes in pri...

Sparse and Dense Indexes These indexes in principle are the similar as that of indexes used at the back of the book. The key facts of the indexes are: They are arranged

Explain heap file with advantages, Explain heap file with advantages? H...

Explain heap file with advantages? Heap File is an unordered set or a group of records, stored on a set of pages. This class gives basic support for inserting, updating, select

What are the responsibility of file manager, What are the responsibility of...

What are the responsibility of File manager? File Manager : Manager allocation of space on disk storage and the data structures used to represent within stored on disk. It is a

Define the term database, QUESTION (a)(i) Define the term database. ...

QUESTION (a)(i) Define the term database. (ii) How is it different from a database management system? (b) What is the difference between an entity and an attribute? (c

Explain data models namely relational network - hierarchical, Explain the t...

Explain the three data models namely relational, network and hierarchical and evaluate their relative advantages and disadvantages. Hierarchical Model: In hierarchical model, da

Describe the definition of a transaction in sql, Describe the definition of...

Describe the definition of a transaction in SQL  Ans: The SQL transaction starts implicitly. Transactions are finished by either Commit work that commits the transaction and st

Modifyand removing a sequence-sequences, Modify a sequence: ALTER SEQU...

Modify a sequence: ALTER SEQUENCE SEQSS INCREMENT 2 MAXVALUE 3000;   Removing a sequence: DROP SEQUENCE SEQSS;

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