Oracle PL/SQL Programming: A Developer's Workbook

Chapter 19. Date Functions

Almost all business applications require dates in one form or another. Often, you have to store the date an order was entered, generate a quarterly sales report, or compute the number of days a bill has gone unpaid. Dates are deceptively complex: they come in dozens of formats, have sophisticated arithmetic rules (quick, what’s May 21, 1994 from February 29, 2000?), and, in general, give most developers fits. Fortunately, Oracle has provided a set of functions that make the job much easier. This chapter tests your ability to work with dates in PL/SQL, covering topics such as converting a formatted string into a DATE variable or performing date arithmetic.

Beginner

19-1.	What function can you use to move a date forward by six months?
19-2.	Write a procedure to display the current date and time so the information looks like this: January 17th, 1999 13:05:44
19-3.	What function can you use to find the date of the last day in the month for a specified date?
19-4.	What function can you use to wipe clean the time component of a date variable?
19-5.	Write a line of code that transforms today’s date to the first date in the current quarter.
19-6.	Write a line of code that calculates the number of whole months between start_date and end_date.
19-7.	Write a line of code that moves a date back 18 years.
19-8.	What is the default time in a variable declared as type DATE?
19-9.	Write a function that returns the number of days left in the current month.