Examine the structure of the SHIPMENTS table:
You want to generate a report that displays the PO_ID and the penalty amount to be paid if the
SHIPMENT_DATE is later than one month from the PO_DATE. The penalty is $20 per day.
Evaluate the following two queries:
Which statement is true regarding the above commands?
A.
Both execute successfully and give correct results.
B.
Only the first query executes successfully but gives a wrong result.
C.
Only the first query executes successfully and gives the correct result.
D.
Only the second query executes successfully but gives a wrong result.
E.
Only the second query executes successfully and gives the correct result.
Explanation:
The MONTHS_BETWEEN(date 1, date 2) function returns the number of months between two dates:
months_between(’01-FEB-2008′, ’01-JAN-2008′) = 1
The DECODE Function
Although its name sounds mysterious, this function is straightforward. The DECODE function implements if
then-else conditional logic by testing its first two terms for equality and returns the third if they are equal and
optionally returns another term if they are not.
DECODE Function Facilitates conditional inquiries by doing the work of a CASE expression or an IFTHENELSE statement:
DECODE(col|expression, search1, result1
[, search2, result2, …, ]
[, default])
DECODE Function
The DECODE function decodes an expression in a way similar to the IF-THEN-ELSE logic that is used in
various languages. The DECODE function decodes expression after comparing it to each search value. If the
expression is the same as search, result is returned.
If the default value is omitted, a null value is returned where a search value does not match any of the result
values.