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

Functional Dependencies, What exactly is the concept of Functional Dependen...

What exactly is the concept of Functional Dependencies? And how do we associate this concept with the logic of Super-keys, Candidate Keys, etc? Given Relation R(A,B,C,D,E) with de

What are axioms, What are axioms? Axioms or rules of inference give a s...

What are axioms? Axioms or rules of inference give a simpler technique for reasoning about

Dependency Diagram, A Structure of a dependency diagram

A Structure of a dependency diagram

How does the system cope up with a record crash, How does the system cope u...

How does the system cope up with a record crash when recovery is going on after the first crash? Ans: In a system the undo and redo operations are needed to be idempotent to c

Data models, why older data models are being replaced by new data models....

why older data models are being replaced by new data models.

Insulation between conceptual and physical structures, Insulation between c...

Insulation between conceptual and physical structures It can be defined as: 1. The Database Administrator should be capable to vary the storage structures without affectin

Define deadlock term, a. Define the term "deadlock". There are four conditi...

a. Define the term "deadlock". There are four conditions that must hold before deadlock is possible. Name them. b. Outline an algorithm that detects whether there is a deadlock.

Create a view that finds the student name, Section A: Use the following ta...

Section A: Use the following tables to create a database called College. Use SQL commands. Student stuid(primary) lastName firstName

I want a professional with strong it background, I want a professional with...

I want a professional with strong IT background who provide me timely assignments Project Description: I want a professional who can do my assignments for my major i.e. Infor

Describes the several relationship constraints, Describes the several relat...

Describes the several relationship constraints through giving suitable example? Constraints on relationships: There are two kinds of constraints on relationships. 1) Mapping

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages