what is the difference between rollback & commit?
can a foreign key has null value?

Answer Posted / ven

Commit made changes permenant to the database.
Rollback made undo the changes.

Yes, FK has null values.

Is This Answer Correct ?    23 Yes 2 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

Can we connect to ORACLE db using Windows Authentication?

937


How does the on-delete-cascade statement work?

853


How to use regular expression in pattern match conditions in oracle?

799


Differentiate between pre-select and pre-query?

838


Explain the use of owner option in exp command.

782


Differentiate between translate and replace?

812


What is an oracle recycle bin?

729


How to call a stored function in oracle?

748


What is user managed backup in Oracle?

838


What view(s) do you use to associate a users SQLPLUS session with his o/s process?

2139


How would you configure your networking files to connect to a database by the name of DSS which resides in domain icallinc.com?

1704


What are the set operators union, union all, minus & intersect meant to do?

761


What do database buffers contain?

763


How do I limit the number of oracle database connections generated by weblogic server?

812


Can we create database in oracle using command line ?

817