what is the difference between primary key & foreign key?
Answer Posted / ansul singh
Primary key is unique key but Foreign key always refers to
primary key.
Primary key is the parent & Foreign key is the child.
Primary key is unique, Primary key is not null and
Foreign key is null, Foreign key reference as primary key
is another table.
Primary key will not allow "Null values" & "Duplication
values",
Foreign key will allow "Null values & "Duplicate values" &
it refers to a primary key is another table.
| Is This Answer Correct ? | 1 Yes | 0 No |
Post New Answer View All Answers
State the difference between a primary key and foreign key?
How many file formats are supported to export data?
What do you mean by a tablespace?
Can we commit inside a function in oracle?
How to connect the oracle server as sysdba?
ur a sql devoloper...what is the process in ur company for finding the database BUGS .. seperate DB testers are there? or devr.s are manage? if DB TESTERS in there what is the process
What are the differences between interval year to month and interval day to second?
How to create a stored function in oracle?
How to name query output columns in oracle?
How to declare a local variable?
How do we represent comments in oracle?
What is index-organized table in Oracle?
What happens to indexes if you drop a table?
Why is oracle database so popular?
How to start instance with a minimal initialization parameter file?