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

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

Heuristics, Benefits of using heuristics

Benefits of using heuristics

Advantages of database systems, Problem 1. Describe the following a)...

Problem 1. Describe the following a) Advantages of Database Systems b) Functions of a DBMS Explanation of part (a) and (b) 2. Explain the following concepts w

Explain different types of keys and relational model., Relational Model: T...

Relational Model: The relational model uses a collection of tables to represent both data and the relationships among those data. Each table has multiple columns and each column h

What are the various states of transaction process, What are the various st...

What are the various states through which a transaction passes through in its lifetime?  Briefly discuss all the events that causes transition from one state to another.   Ans:

Explain the log based recovery method, Explain the Log Based Recovery Metho...

Explain the Log Based Recovery Method? The system log that is generally written on stable storage consists of the redundant data required to recover from volatile storage failu

What are the several kinds of the update operations relation, What are the ...

What are the several kinds of the update operations on relations? Also explain the constraints on these update operation. Give instance in support of your answer. There are th

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