ORACLE DATABASE INTERVIEW QUESTIONS

What is a DEFAULT constraint in Oracle, and why is it used?

How do you define a DEFAULT value for a column when creating a table?

What happens if you insert a row without specifying a value for a column that has a DEFAULT constraint?

Can you provide an example of using a function as a DEFAULT value for a column?

How can you add a DEFAULT constraint to an existing column in a table?

How do you remove a DEFAULT constraint from a column?

How do DEFAULT constraints interact with NOT NULL constraints in Oracle?

Can you use expressions as default values in Oracle? Provide an example?

What is the behavior of DEFAULT constraints when inserting rows using INSERT INTO ... SELECT statements?

Explain how to use DEFAULT constraints in combination with other constraints to enforce business rules. Provide an example?