Home arrow Oracle arrow Page 2 - Working With Oracle on Windows: Part 2
ORACLE

Working With Oracle on Windows: Part 2


Now we have installed Oracle we can now begin to familiarise ourselves with use of SQL and how to use basic Oracle expressions.

Author Info:
By: Ben Shepherd
Rating: 4 stars4 stars4 stars4 stars4 stars / 17
March 04, 2003
TABLE OF CONTENTS:
  1. · Working With Oracle on Windows: Part 2
  2. · Databases
  3. · Relationships
  4. · Structuring your database
  5. · Tables in Oracle
  6. · User Defined Schema Objects
  7. · Conclusion

print this article
SEARCH DEVARTICLES

Working With Oracle on Windows: Part 2 - Databases
(Page 2 of 7 )

Since this is only the second of my series, it is important to refresh your knowledge of SQL (i.e. Structured Query Language). As this series progresses the use of SQL will become more sophisticated. Don’t worry about it. You will be able to understand the code when that time comes.

In my last article, there were a number of people that did not quite understand the code. So, let’s start from the beginning. A database it quite useless without a table. Oracle 9i, which we should already have registered and installed, contains a feature called SQL*Plus.

You have now read the article and have understood how database is created. Create the database and startup an instance. There is nothing useful inside your database so far. A database may contain at least a table. The table will allow you to store the data in various fields. Well designed tables contain a field which is called a primary key. A primary key is a field in which is used to identify the record/s in the table.

Two important details about a primary key is that it can not be a null value (i.e. each field must contain a value) and it must have a unique value. This is important because the reason for a primary key is to uniquely identify each record. Imagine if someone had the same credit card number as you … yikes!!!

It is possible to have more than one primary key (i.e. a composite primary key) – like in a barcode – where there is three parts.

If you have more than one table and you wish to have the two tables related in some way you can by introducing a foreign key. A foreign key is a field in a table that is used to uniquely identify a record in another table. This introduces relationships between tables.


blog comments powered by Disqus
ORACLE ARTICLES

- Oracle Purchases Taleo to Extend Cloud Compu...
- Partitioning in Oracle. What? Why? When? Who...
- Datatypes Used in Oracle 9i
- Creating a Database in Oracle 9i
- Oracle with Doctor Janusz Getta
- Working With Oracle on Windows: Part 3
- Working With Oracle on Windows: Part 2

Watch our Tech Videos 
Dev Articles Forums 
 RSS  Articles
 RSS  Forums
 RSS  All Feeds
Write For Us 
Weekly Newsletter
 
Developer Updates  
Free Website Content 
Contact Us 
Site Map 
Privacy Policy 
Support 

Developer Shed Affiliates

 




© 2003-2017 by Developer Shed. All rights reserved. DS Cluster - Follow our Sitemap
Popular Web Development Topics
All Web Development Tutorials