My SQL statement SELECT AVG(SALARY) FROM EMP-TABLE yields inaccurate results. why?

COBOL SQL Interview Questions

(Continued from previous question...)

My SQL statement SELECT AVG(SALARY) FROM EMP-TABLE yields inaccurate results. why?

Because SALARY is not declared to have Null's and the employees for whom the salary is not known are also counted

(Continued on next question...)

Other Interview Questions

• Where in a table are added column located ?
• How do you concatenate the FIRSTNAME and LASTNAME from EMP table to give a complete name?
• What is a Cartesian product?
• What is the use of VALUE function?
• What is a Cartesian product?
• What are foreign keys?
• When do you use a LINK statement ?
• In the WHERE clause what is BETWEEN and IN?
• How do you concatenate the FIRSTNAME and LASTNAME from EMP table to give a complete name?
• What is an index key?
• More...