what is the difference between primary key & foreign key?
Answer Posted / afzaal
primary key is a constraint key that can not contain a null
or duplicate values.
foriegn key is a reference key ,before referencing the
foriegn key parent table field or fields must have primary
key.If u can try to insert a value in referencing field,new
record that must contain parent field.
| Is This Answer Correct ? | 22 Yes | 11 No |
Post New Answer View All Answers
How to do clean up if create database failed?
What is a tns file?
What is the difference between alert log file and tarce file ?
How to convert characters to times in oracle?
What is max rowid in oracle?
How would you go about verifying the network name that the local_listener is currently using?
What is the scope of a local variable?
How to create a new oracle data file?
How to use attributes of the implicit cursor in oracle?
How can you tell how much space is left on a given file system and how much space each of the file systems subdirectories take-up?
Point out the difference between user tables and data dictionary?
Assuming that you are an End User How to find that in the payment Batch some of the Invoice was Missing To pay How to find That??
what is IDE,DMV in sql server?
What is catalog in Oracle?
What are the various oracle database objects?