Interested to Buy Any Domain ? << Click Here >> for more details...
What is the main different between Null and NOT Null.
Difference between Primary and Unique Key.
How to Check the database from which application is it
possibe.
- 6 Answers
- 8735 Views
- I also Faced
- E-Mail Answers
Answer Posted / kalpana
Primary key can never be NULL.it is used to uniquely
identify the row in a table.The database engine requeir a
value to relocate the record.so Primary key can never be
NUL.unique key may be NULL.
| Is This Answer Correct ? | 21 Yes | 0 No |
Post New Answer View All Answers
How do I completely remove mysql from windows?
What is mysql port?
Differentiate CHAR_LENGTH and LENGTH?
What is save point in mysql?
Consider a scenario where you have two to three tables with thousand tuples in each of them. Now, if you have to perform a join operation between them will you choose to perform filtering of rows or transforming of rows first.
Can you tell few best practices to be followed for optimization in sql?
How many tables we can create in mysql database?
Is sqlite faster than mysql?
What is a session in mysql?
What is delimiter $$?
What is unsigned int in mysql?
How Switch (select or use) to a database.
How MySQL Optimizes DISTINCT?
What are date and time data types in mysql?
Is primary key auto increment?
