emp numb is unique because that is primary key,,but what is foreign key .. explain very clear with example
Answer Posted / vilas
Foregin key: It is the relation between two tables.it can be
used to create the relation between two tables,when two
tables have the unique rows (means emp_numb)then we can
used to foreign key.
eg:
create table student
{ name varchar(10),
rollno int(10));
.......this is student table........
create table student_Details
{ name varchar(10),
rollno int(10)refercence
);
.
| Is This Answer Correct ? | 3 Yes | 0 No |
Post New Answer View All Answers
How many anonymous blocks can be defined?
What is the purpose of tables, private synonyms and public synonyms in Oracle?
how to join query for one source type is oracle another source type is sql server ?
How to run create database statement?
How to speed up webrick?
What is the relationship among database, tablespace and data file?
What is oracle rownum?
How would you go about verifying the network name that the local_listener is currently using?
How do I know if oracle client is installed on windows?
What is the difference between primary key and unique key and foreign key in oracle?
What is using clause and give example?
How to retrieve values from data fields in record variables?
Is there any way to find out when one specific table/view/M-view is used last time. i.e. when one specific object is used in any SELECT statement.
Can you drop an index associated with a unique or primary key constraint?
Explain self joins in oracle?