what is the difference between primary key & foreign key?
- 57 Answers
- 122462 Views
- CTS, Infosys, La Multi, Sparsh, Wipro, I also Faced
- E-Mail Answers
Answer Posted / sripathi venkata ramesh
I am Sripathi Venkata Ramesh from Gudivada and the answer
is mentioned below
Primary key: A Primary key is a column or group of columns
used to uniquely identify each row in a table like
It defines the column as a Mandatory column.
The data held across the column must be unique.
By default it creates clustered index.
It does not allow null values and duplicate values
Foreign key: A Foreign key is a column or group of columns
whose values are derived from the primary key of some other
table
| Is This Answer Correct ? | 2 Yes | 2 No |
Post New Answer View All Answers
How can we delete duplicate rows in a table?
What are the different types of partitions in oracle?
Please explain oracle data types with examples?
6. Display the client name and order date for all orders using the traditional method.
For a field in a repeating frame, can the source come from the column which does not exist in the data group which forms the base for the frame ?
What is SQL access advisor in Oracle?
How to bring a tablespace offline?
How to fetch the row which has the max value for a column?
How will you write a query to get a 5th rank student from a table student_report?
what is difference between sql plus and sql*plus? (not sql and sql plus).
What privilege is needed for a user to delete rows from tables in another schema?
Explain the difference between replace() and translate() functions in oracle?
How to write numeric literals in oracle?
What is an external table?
What is the difference between hot backup and cold backup in oracle? Tell about their benefits also.
