PL/SQL Interview Questions and Answers

Q. What does the following query do?


A: SELECT SAL + NVL(COMM,0) FROM EMP;?
This displays the total salary of all employees. The null values in the commission column will be replaced by 0 and added to salary.




Q. What is the advantage of specifying WITH GRANT OPTION in the GRANT command?


A: The privilege receiver can further grant the privileges he/she has obtained from the owner to any other user.




Q. Which command executes the contents of a specified file?


A: START or @.




Q. What is the value of comm and sal after executing the following query if the initial value of ‘sal’ is 10000
UPDATE EMP SET SAL = SAL + 1000, COMM = SAL*0.1;?


A: sal = 11000, comm = 1000.




Q. Which command displays the SQL command in the SQL buffer, and then executes it?


A: RUN.




Q. What command is used to get back the privileges offered by the GRANT command?




A: REVOKE.




Please click here for more