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 At :: csc
 Question Submitted By :: kamaltimalsina012
I also faced this Question!!    
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 get only updated, deleted , inserted records after certain interval time in mysql with out using triggers... 604
using primary can we relate two table, with out foreign key? 1060
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 ? 554
What is striped backup 624
How to define numeric 9(3) in db2 table without decimal point?? 871
What are the method you will follow while sql installing 739
How internally data stores in MyISAM and INNODB table types? 726
How can you plan the logshipping before processing? 629
Have you ever used MySQL Administrator and MySQL Query Browser? Describe the tasks you accomplished with these tools? 1875
explain GROUPBY & HAVING clause with examples. 643
Can u give the example by taking an unnormalized table and make that 1nf and then 25nf, and then 3 nf? 2559
How to set the time zone for MySQL to particular country time? 1573
How to enable or disable a row of a table using MySQL in struts? 1695
all the queries used in sql 924
What are the critical issues you have resolved in your company 542
E-Mail New Answers        Answer Selected Questions