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

Define blocks, Define blocks? The database system resides eternally on ...

Define blocks? The database system resides eternally on non-volatile storage, and is into fixed-length storage units known as blocks.

What are the purpose for having variable length records, What are the purpo...

What are the purpose for having variable length records? What kinds of separator characters are required for each? Variable-Length Records - Variable-length records are thos

A Biological Database on Viruses, How to create a biological database based...

How to create a biological database based on viruses. How to decide which attribute should be there in the table and schema? How to identify the primary keys, foreign keys, domain,

What are the storage types, What are the storage types? The storage typ...

What are the storage types? The storage types are: a) Volatile storage b) Nonvolatile storage

Explain the disadvantages of file oriented approach, Explain the disadvanta...

Explain the disadvantages of file oriented approach? In the oriented approach Applications are designed in isolation. Design of application is optimized for one application. In

What are the various properties of relational tables, What are the various ...

What are the various properties of Relational tables? Relational tables have 6 properties: 1. Each row is unique. 2. Column values are of the same kind. 3. Values are

Explain odbc, Explain ODBC? ODBC - Open DataBase Connectivity (ODBC) e...

Explain ODBC? ODBC - Open DataBase Connectivity (ODBC) enable the integration of SQL along with a general-reasons programming language.

Creating a view-data control, Creating a view: A query can be embed...

Creating a view: A query can be embedded within the CREATE VIEW STATEMENT A query can have complex select statements containing join, groups and sub- queries A quer

Sequential file organisation, Sequential File Organisation The most nec...

Sequential File Organisation The most necessary way to organise the collection of records in a file is to use sequential Organisation. Records of the file are stored in series

Database Models, Benefits and Limitations od Data Models?

Benefits and Limitations od Data Models?

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