Solved

Primary key Vs Unique key

Posted on 2004-09-09
2
4,974 Views
Last Modified: 2008-01-09
Is there any point in declaring a primary key if I already have a unique clustered index on the primary key field(s)?
0
Comment
Question by:billy21
2 Comments
 
LVL 5

Accepted Solution

by:
hkamal earned 350 total points
ID: 12018118
Yes, all tables should have a primary key
This just formalises your structure for inter-entity relationships
0
 
LVL 15

Expert Comment

by:jdlambert1
ID: 12018444
I agree with hkamal that all tables should have a primary key. I've heard many reasons why people didn't define them for some tables, but I don't buy the arguments. It's a best practice and a good habit. If you define a primary key on a table and it actually never "needed", no harm is done. If you don't define a primary key because you're "sure" it will never be needed, but you turn out to be wrong, great harm can be done. And I've seen a great many databases that were in extremely bad shape because of failures including lack of primary keys where people didn't think they were needed.
0

Featured Post

PRTG Network Monitor: Intuitive Network Monitoring

Network Monitoring is essential to ensure that computer systems and network devices are running. Use PRTG to monitor LANs, servers, websites, applications and devices, bandwidth, virtual environments, remote systems, IoT, and many more. PRTG is easy to set up & use.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Introduction In my previous article (http://www.experts-exchange.com/Microsoft/Development/MS-SQL-Server/SSIS/A_9150-Loading-XML-Using-SSIS.html) I showed you how the XML Source component can be used to load XML files into a SQL Server database, us…
This article shows gives you an overview on SQL Server 2016 row level security. You will also get to know the usages of row-level-security and how it works
Via a live example, show how to backup a database, simulate a failure backup the tail of the database transaction log and perform the restore.
Viewers will learn how to use the SELECT statement in SQL to return specific rows and columns, with various degrees of sorting and limits in place.

776 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question