what is the difference between rollback & commit?
can a foreign key has null value?
Answer Posted / vaibhavi_dixit
With commit, all the changes, which are made using insert,
update or delete SQL statments, are save permanently in the
table(ie DB).Whereas, if one want to undo the changes made
by DML statments, then before issuing commit, one can use
rollback statment.Rollback statment has no effect, if used
after commit.
Yes foreign key can have null value.
| Is This Answer Correct ? | 9 Yes | 1 No |
Post New Answer View All Answers
How to view all columns in an existing table?
Does oracle charge for java?
Explain the use of indexes option in imp command.
How can we view last record added to a table?
What happens to the current transaction if the session is killed?
What is the order of defining local variables and sub procedures/functions?
What are the differences between number and binary_float in oracle?
What is an anonymous block?
How many types of table in Oracle?
Explain what are the characteristics of data files?
What are the advantages of oracle?
What is the fastest query method to fetch data from the table?
How are extents allocated to a segment?
How to update values on multiple rows in oracle?
How do you find current date and time in oracle?