ALLInterview.com :: Home Page
 Advertise your Business Here     
Browse  |   Placement Papers  |   Company  |   Code Snippets  |   Certifications  |   Visa Questions
Post Question  |   Post Answer  |   My Panel  |   Search  |   Articles  |   Topics  |   Errors
   Testimonials Refer this Site  Refer This Site to Your Friends  Site Map  Contact Us      
   
 
Categories >> Software >> Databases >> MySQL
 


 

 
Question What is the difference between primary and unique key
 Question Asked In Companies :: CSC,     < I also faced this Question! >
 Question Submitted By :: kamaltimalsina012
  Answer Posted By  
 
Answer
Primay key restrict the duplicacy in the records and does
not accept null value or there are only one primary key in
a table

Unique constraint also restict the duplicacy but it accept
the null value one or more then one. We can apply unique
constraint more than one column

Is This Answer Correct ?    2 Yes 2 No


 
  ashish asthana
 
View All Answers
 
 
Please Help Members By Posting Answers For Below Questions
 
 Question Views   Select
 
How to set the time zone for MySQL to particular country time? 1588
In a property booking section want a query to check that property is booked from StartDate to EndDate.Booking Table field are given id proerty_id start_date checkout_date no_of_visitor booking date status Waiting yours answer.. Thanks In Advance... 997
How to define numeric 9(3) in db2 table without decimal point?? 891
Can u give the example by taking an unnormalized table and make that 1nf and then 25nf, and then 3 nf? 2613
Explain the architecture models of SQL Server? 652
why not null is not allowed at table level 707
Hi Team, This is kartik, I recently completed my B-tech. Importance of posting this question is for to know the best books on SQL(MYSQL/Oracle)? I like SQL concept's so much, at the same time i decided to choose SQL for my career purpose. So please suggest me the best books that are very helpful for a fresher to improve concepts like (SQL/PLSQL)Basics, programming concepts, architectures etc. Please consider my request as an important one. I am very thankful to you for providing this opportunity. If possible can you please send the names of books for my personal id also: karthikgdv1206@yahoo.com. Thanks, Kartik T 600
what is mysql optimization in brief? 718
I've looked but can't find a MySQL equivalent for MS SQL's xp_cmdshell. I have 7z files that I want to unzip and load into MySQL. I'm trying to write a sp to do the unzip, but I can't find a way to do that. Can anyone provide an example of a similar process in Windows? TIA. 1262
suppose data is copie to oracle to sql by using DTS. Actully it taken 2 hours. suppose some day distribute the server in the middle of 2 hours. after how can i get the data ? 559
I want to insert userid of a customer,order time,etc in a table called ordermaster with orderid as primary key.Same time the product codes and required quantities (a1,2 and a2 4 and so on)inserted in another table orderdetails with same orderid reference.How the code will be in JSP using MySQL? 409
1.how to fetch a value and Execute store procudure in mysql(INNODB) using phpMyAdmin? 2.can i wright a package in mysql database(INNODB)? 511
all the queries used in sql 935
using primary can we relate two table, with out foreign key? 1071
What is RMS Migrations 650
E-Mail New Answers        Answer Selected Questions