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

A step-wise distributed database design methodology, A step-wise distribute...

A step-wise distributed database design methodology Following is a step-wise methodology for distributed database design. (1) Examine the nature of distribution. Find out wh

Express types of information available in mysql, Express types of informati...

Express types of information available in MySQL? Information as regards the result of queries:  This includes number of records affected by any SELECT or UPDATE or DELETE st

What are the different integrity constraints in rdbms, What are the differe...

What are the different integrity constraints in RDBMS? The various integrity constraints in RDBMS are as: Primary Key: primary key is a grouping of one or more attributes

Define query language, Define query language?   A query is a statement ...

Define query language?   A query is a statement requesting the retrieval of information. The portion of DML that includes information retrieval is known as a query language.

Give short note on the following terms- dirty pages and etl, Give short not...

Give short note on the following terms:Dirty pages and ETL a.) Dirty pages. These are buffer pages which comprise modifications which haven't been written to disk. b.

Write short notes on relational model, Write short notes on relational mode...

Write short notes on relational model The relational model uses a collection of tables to show both data and the relationships between those data. The relational model is an ex

Design a gennalization and specialization hierarchy for an a, Design a genn...

Design a gennalization and specialization hierarchy for an automobile sales company

What is the aim of object design, What is the aim of object design The ...

What is the aim of object design The aim of object design is to identify object which the system   contains and the interactions among them. The system implements specification

Explain the concept of two-phase locking, Explain the Concept of Two-phase ...

Explain the Concept of Two-phase Locking It concerns the positions of locking and unlocking operations in each transaction.  In this protocol every transaction issue lock and u

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