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 bcnf boyce-codd normal form, BCNF Boyce-Codd Normal Form A rel...

BCNF Boyce-Codd Normal Form A relation schema R is in BCNF if it is in 3NF and accepts an additional constraint that for every FD X A, X has to be a candidate key. If a relati

Heap files (unordered file), Heap files (unordered file) Mostly these f...

Heap files (unordered file) Mostly these files are unordered files. It is the easiest and most basic type. These files having of randomly ordered records. The records will have

I need label printing program, Project Description: Hi I'm seeking someo...

Project Description: Hi I'm seeking someone to make my dBase application work. I know it's not a 'modern' language but it's what I know. I have written an order program and I ne

Dbms built for online transaction processing, Problem: A DBMS built for...

Problem: A DBMS built for Online Transaction Processing (OLTP) is usually regarded as unsuitable for data warehousing. Each system is designed with a different set of requireme

Skills required, wrie a report on whether a BSc n information systems devel...

wrie a report on whether a BSc n information systems develops the skills required by employers in Database administration

Explain the concept of data mining, Question 1 Explain the concept of Fore...

Question 1 Explain the concept of Foreign Key. How a foreign key differs from a Primary Key? Can the Foreign Key accept nulls? Question 2 With a necessary example explain (i)

Define physical and logical data independence, Define physical and logical ...

Define physical and logical data independence. How does this architecture help in achieving these? Data independence entails that change in one view must not need a change in t

What are called journaling file systems, What are called journaling file sy...

What are called journaling file systems? File systems that support log disks are known as journaling file systems.

Which is another name for weak entity, Which is another name for weak entit...

Which is another name for weak entity? Child is another name of weak entity.

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