Explain the exists and unique functions of sql, Database Management System

Assignment Help:

Explain the EXISTS and UNIQUE functions of SQL. Give an example for each?

EXISTS: The EXISTS function takes one parameter that is a SQL statement. If any records exist which match the criteria it returns true, or else it returns false. This provides you a clean, well-organized way to write a stored procedure in which does either an insert or update.

UNIQUE: If UNIQUE is particular then only unique values are used to compute the mean.


Related Discussions:- Explain the exists and unique functions of sql

What is called as an n-way merge, What is called as an N-way merge? The...

What is called as an N-way merge? The merge operation is a generalization of the two-way merge used by the standard in-memory sort-merge algorithm. It merges N runs, so it is k

Describe the static hash file with buckets and chaining, Describe the stati...

Describe the static hash file with buckets and chaining and show how insertion, deletion and modification of a record can be performed. In static hash file organization, the wo

Rules of data normalisation, Rules Of Data Normalisation  Let us now su...

Rules Of Data Normalisation  Let us now summarise Normalisation with the help of various clean rules. The following are the necessary rules for the Normalisation process: 1.

Construct a conceptual data model, Competition entrants can be either Indiv...

Competition entrants can be either Individuals, or Teams. A Team is usually sponsored by a business, and, in that case, the team members would all wear T-shirts with the sponsoring

Explain the 10 reasons to use mysql, Question 1 Explain the 10 reasons to ...

Question 1 Explain the 10 reasons to use MySQL Question 2 Write the SQL statements to demonstrate the following using SELECT command Expression Evaluation ORDER BY

Balance transfer, Scenario 1: Power goes out after the first instruction. ...

Scenario 1: Power goes out after the first instruction. What happens?

Trigger , Flights(FlightNo, DeptDateTime, Origin, ArrivalDateTime, Destinat...

Flights(FlightNo, DeptDateTime, Origin, ArrivalDateTime, Destination, Capacity, SoldSeats) Tickets(FlightNo, Seat, CustID) Where - flightNo is the PK of the flights table - DeptDa

Define the traditional system analysis and design, Define the Traditional S...

Define the Traditional System Analysis and Design Traditional System Analysis and Design (SAD) have three basic life cycle models. A typical software lifecycle consists of the

What are the four main characteristics of the database, What are the four m...

What are the four main characteristics of the database approach? The four major characteristics of the database approach are: 1. Self-describing nature of a database system. 2.

Illustrate how customer relationship is promoted, FitAll Ltd is a company t...

FitAll Ltd is a company that manufactures clothes. Its processes are manual and there are stand-alone Information Systems that aid to manage them. The Information Systems were purc

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