what is difference between primary key and unique key
?
Answer Posted / ashish tyagi
The basic difference between primary key and unique key is that unique key allows null value but primary key did not allow null value.
| Is This Answer Correct ? | 2 Yes | 0 No |
Post New Answer View All Answers
Explain about the storage and physical database design?
Explain about xml databases?
What are the 18 schemas?
Explain about query and reporting.
On friday, you issued several insert statements using query analyzer. You then verified the data had been correctly entered with a select statement on monday, your users report that the data is not there what happened?
Explain about normal forms?
Where is dbms used?
What is the physical representation for a many-to-many relationship?
There is a trigger defined for INSERT operations on a table, in an OLTP system. The trigger is written to instantiate a COM object and pass the newly insterted rows to it for some custom processing. What do you think of this implementation? Can this be implemented better?
I HAVE A PI ON COL A THE NEXT DAY I WANT CHANGE THE PI ON COL B? PLS SEND ME THE ANS
Can an extended stored procedure be called from inside a user-defined function?
What is dbms and its application?
Explain about relational operator join?
How to read and create .LDC data files which are used by linguatic dictionary.
How can you fix a poorly performing query?