The EMPLOYEES table has these columns:
LAST NAME. VARCHAR2(35)
SALARY. NUMBER(8, 2)
HIRE_DATE. DATE
Management wants to add a default value to the SALARY column. You plan to alter the table by using this SQL
statement:
ALTER TABLE EMPLOYEES
MODIFY (SALARY DEFAULT 5000);What is true about your ALTER statement?
A.
Column definitions cannot be altered to add DEFAULT values.
B.
A change to the DEFAULT value affects only subsequent insertions to the table.
C.
Column definitions cannot be altered at add DEFAULT values for columns with a NUMBER data type.
D.
All the rows that have a NULL value for the SALARY column will be updated with the value 5000.
Explanation:
A change to the DEFAULT value affects only subsequent insertions to the table. Existing rows will not be
affected.
Incorrect Answers
A:. Column definitions can be altered to add DEFAULT values.
C:. Column definitions can be altered to add DEFAULT values. It works for columns with a NUMBER data type
also.
D:. A change to the DEFAULT value affects only subsequent insertions to the table. Existing rows will not be
affected.
OCP Introduction to Oracle 9i: SQL Exam Guide, Jason Couchman, p. 219-224
Chapter 5: Creating Oracle Database Objects