QUESTION 11
Examine the structure of the PROGRAMS table:
name Null Type
—— ——— ——-
PROG_ID NOT NULL NUMBER(3)
PROG_COST NUMBER(8,2)
START_DATE NOT NULL DATE
END_DATE DATE
Which two SQL statements would execute successfully? (Choose two.)
A. SELECT NVL(ADD_MONTHS(END_DATE,1),SYSDATE)
FROM programs;
B. SELECT TO_DATE(NVL(SYSDATE-END_DATE,SYSDATE))
FROM programs;
C. SELECT NVL(MONTHS_BETWEEN(start_date,end_date),’Ongoing’)
FROM programs;
D. SELECT NVL(TO_CHAR(MONTHS_BETWEEN(start_date,end_date)),’Ongoing’) FROM programs;
Answer: AD
Explanation:
NVL Function
Converts a null value to an actual value:
Data types that can be used are date, character, and number.
Data types must match:
NVL(commission_pct,0)
NVL(hire_date,’01-JAN-97′)
NVL(job_id,’No Job Yet’)
MONTHS_BETWEEN(date1, date2): Finds the number of months between date1 and date2 The result can be positive or negative. If date1 is later than date2, the result is positive; if date1 is earlier than date2, the result is negative. The noninteger part of the result represents a portion of the month.
MONTHS_BETWEEN returns a numeric value. – answer C NVL has different datatypes – numeric and strings, which is not possible!
The data types of the original and if null parameters must always be compatible. They must either be of the same type, or it must be possible to implicitly convert if null to the type of the original parameter. The NVL function returns a value with the same data type as the original parameter.
QUESTION 12
The PRODUCTS table has the following structure:
name Null Type
—— ——— ——-
PROD_ID NOT NULL NUMBER(4)
PROD_NAME VARCHAR2(25)
PROD_EXPIRY_DATE DATE
Evaluate the following two SQL statements:
SQL>SELECT prod_id, NVL2(prod_expiry_date, prod_expiry_date + 15,”)
FROM products;
SQL>SELECT prod_id, NVL(prod_expiry_date, prod_expiry_date + 15)
FROM products;
Which statement is true regarding the outcome?
A. Both the statements execute and give different results.
B. Both the statements execute and give the same result.
C. Only the first SQL statement executes successfully.
D. Only the second SQL statement executes successfully.
Answer: A
Explanation:
Using the NVL2 Function
The NVL2 function examines the first expression. If the first expression is not null, the NVL2 function returns the second expression. If the first expression is null, the third expression is returned.
Syntax
NVL2(expr1, expr2, expr3)
In the syntax:
expr1 is the source value or expression that may contain a null expr2 is the value that is returned if expr1 is not null expr3 is the value that is returned if expr1 is null
QUESTION 13
Examine the structure of the INVOICE table.
Name Null Type
—— ——— ——-
INV_NO NOT NULL NUMBER(3)
INV_DATE DATE
INV_AMT NUMBER(10,2)
Which two SQL statements would execute successfully? (Choose two.)
A. SELECT inv_no,NVL2(inv_date,’Pending’,’Incomplete’)
FROM invoice;
B. SELECT inv_no,NVL2(inv_amt,inv_date,’Not Available’)
FROM invoice;
C. SELECT inv_no,NVL2(inv_date,sysdate-inv_date,sysdate)
FROM invoice;
D. SELECT inv_no,NVL2(inv_amt,inv_amt*.25,’Not Available’)
FROM invoice;
Answer: AC
Explanation:
The NVL2 Function
The NVL2 function provides an enhancement to NVL but serves a very similar purpose. It evaluates whether a column or expression of any data type is null or not.
5-6 The NVL function\
If the first term is not null, the second parameter is returned, else the third parameter is returned. Recall that the NVL function is different since it returns the original term if it is not null. The NVL2 function takes three mandatory parameters. Its syntax is NVL2(original, ifnotnull, ifnull), where original represents the term being tested. Ifnotnull is returned if original is not null, and ifnull is returned if original is null. The data types of the ifnotnull and ifnull parameters must be compatible, and they cannot be of type LONG.
They must either be of the same type, or it must be possible to convert ifnull to the type of the ifnotnull parameter. The data type returned by the NVL2 function is the same as that of the ifnotnull parameter.
QUESTION 14
View the Exhibit and evaluate the structure and data in the CUST_STATUS table.
You issue the following SQL statement:
SQL> SELECT custno, NVL2(NULLIF(amt_spent, credit_limit), 0, 1000)”BONUS”
FROM cust_status;
Which statement is true regarding the execution of the above query?
A. It produces an error because the AMT_SPENT column contains a null value.
B. It displays a bonus of 1000 for all customers whose AMT_SPENT is less than CREDIT_LIMIT.
C. It displays a bonus of 1000 for all customers whose AMT_SPENT equals CREDIT_LIMIT, or
AMT_SPENT is null .
D. It produces an error because the TO_NUMBER function must be used to convert the result of
the NULLIF function before it can be used by the NVL2 function.
Answer: C
QUESTION 15
Which statement is true regarding the COALESCE function?
A. It can have a maximum of five expressions in a list.
B. It returns the highest NOT NULL value in the list for all rows.
C. It requires that all expressions in the list must be of the same data type.
D. It requires that at least one of the expressions in the list must have a NOT NULL value.
Answer: C
QUESTION 16
View the Exhibit and examine the structure of the PROMOTIONS table.
Using the PROMOTIONS table, you need to find out the average cost for all promos in the ranges $0-2000 and $2000-5000 in category A
You issue the following SQL statement:
SQL>SELECT AVG(CASE
WHEN promo_cost BETWEEN 0 AND 2000 AND promo_category=’A’
then promo_cost
ELSE null END) “CAT_2000A”,
AVG(CASE
WHEN promo_cost BETWEEN 2001 AND 5000 AND promo_category=’A’
THEN promo_cost
ELSE null END) “CAT_5000A”
FROM promotions;
What would be the outcome?
A. It executes successfully and gives the required result.
B. It generates an error because NULL cannot be specified as a return value.
C. It generates an error because CASE cannot be used with group functions.
D. It generates an error because multiple conditions cannot be specified for the WHEN clause.
Answer: A
Explanation:
CASE Expression
Facilitates conditional inquiries by doing the work of an IF-THEN-ELSE statement:
CASE expr WHEN comparison_expr1 THEN return_expr1
[WHEN comparison_expr2 THEN return_expr2
WHEN comparison_exprn THEN return_exprn
ELSE else_expr]
END
QUESTION 17
View the Exhibit and examine the structure of the PROMOTIONS table.
Which SQL statements are valid? (Choose all that apply.)
A. SELECT promo_id, DECODE(NVL(promo_cost,0), promo_cost,
promo_cost * 0.25, 100) “Discount”
FROM promotions;
B. SELECT promo_id, DECODE(promo_cost, 10000,
DECODE(promo_category, ‘G1’, promo_cost *.25, NULL),
NULL) “Catcost”
FROM promotions;
C. SELECT promo_id, DECODE(NULLIF(promo_cost, 10000),
NULL, promo_cost*.25, ‘N/A’) “Catcost”
FROM promotions;
D. SELECT promo_id, DECODE(promo_cost, >10000, ‘High’,
<10000, ‘Low’) “Range”
FROM promotions;
Answer: AB
Explanation:
The DECODE Function
Although its name sounds mysterious, this function is straightforward. The DECODE function implements ifthen-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. The DECODE function takes at least three mandatory parameters, but can take many more. The syntax of the function is DECODE(expr1,comp1, iftrue1, [comp2,iftrue2…[ compN,iftrueN]], [iffalse]).
QUESTION 18
Examine the data in the PROMO_BEGIN_DATE column of the PROMOTIONS table:
PROMO_BEGIN _DATE
——————-
04-jan-00
10-jan-00
15-dec-99
18-oct-98
22-aug-99
You want to display the number of promotions started in 1999 and 2000.
Which query gives the correct output?
A. SELECT SUM(DECODE(SUBSTR(promo_begin_date,8),’00’,1,0)) “2000”, SUM(DECODE(SUBSTR
(promo_begin_date,8),’99’,1,0)) “1999”
FROM promotions;
B. SELECT SUM(CASE TO_CHAR(promo_begin_date,’yyyy’) WHEN ’99’ THEN 1 ELSE 0 END) “1999”,
SUM(CASE TO_CHAR(promo_begin_date,’yyyy’) WHEN ’00’ THEN 1 ELSE 0 END) “2000”
FROM promotions;
C. SELECT COUNT(CASE TO_CHAR(promo_begin_date,’yyyy’) WHEN ’99’ THEN 1 ELSE 0 END) “1999”,
COUNT(CASE TO_CHAR(promo_begin_date,’yyyy’) WHEN ’00’ THEN 1 ELSE 0 END) “2000”
FROM promotions;
D. SELECT COUNT(DECODE(SUBSTR(TO_CHAR(promo_begin_date,’yyyy’), 8), ‘1999’, 1, 0)) “1999”, COUNT(DECODE(SUBSTR(TO_CHAR(promo_begin_date,’yyyy’), 8),’2000′, 1,
0)) “2000”
FROM promotions;
Answer: A
QUESTION 19
Examine the structure of the TRANSACTIONS table:
name Null Type
————- ———– ——————–
TRANS_ID NOT NULL NUMBER(3)
CUST_NAME VARCHAR2(30)
TRANS_DATE TIMESTAMP
TRANS_AMT NUMBER(10,2)
You want to display the date, time, and transaction amount of transactions that where done before 12 noon.
The value zero should be displayed for transactions where the transaction amount has not been entered.
Which query gives the required result?
A. SELECT TO_CHAR(trans_date,’dd-mon-yyyy hh24:mi:ss’),
TO_CHAR(trans_amt,’$99999999D99′)
FROM transactions
WHERE TO_NUMBER(TO_DATE(trans_date,’hh24′)) < 12 AND COALESCE(trans_amt,NULL)<>NULL;
B. SELECT TO_CHAR(trans_date,’dd-mon-yyyy hh24:mi:ss’),
NVL(TO_CHAR(trans_amt,’$99999999D99′),0)
FROM transactions
WHERE TO_CHAR(trans_date,’hh24′) < 12;
C. SELECT TO_CHAR(trans_date,’dd-mon-yyyy hh24:mi:ss’),
COALESCE(TO_NUMBER(trans_amt,’$99999999.99′),0)
FROM transactions
WHERE TO_DATE(trans_date,’hh24′) < 12;
D. SELECT TO_DATE (trans_date,’dd-mon-yyyy hh24:mi:ss’),
NVL2(trans_amt,TO_NUMBER(trans_amt,’$99999999.99′), 0)
FROM transactions
WHERE TO_DATE(trans_date,’hh24′) < 12;
Answer: B
QUESTION 20
Examine the structure of the TRANSACTIONS table:
name Null Type
———– ———– ——————–
TRANS_ID NOT NULL NUMBER(3)
CUST_NAME VARCHAR2(30)
TRANS_DATE DATE
TRANS_AMT NUMBER(10,2)
You want to display the transaction date and specify whether it is a weekday or weekend.
Evaluate the following two queries:
SQL>SELECT TRANS_DATE,CASE
WHEN TRIM(TO_CHAR(trans_date,’DAY’)) IN (‘SATURDAY’,’SUNDAY’) THEN ‘weekend’
ELSE ‘weekday’
END “Day Type”
FROM transactions;
SQL>SELECT TRANS_DATE, CASE
WHEN TO_CHAR(trans_date,’DAY’) BETWEEN ‘MONDAY’ AND ‘FRIDAY’ THEN ‘weekday’
ELSE ‘weekend’
END “Day Type”FROM transactions;
Which statement is true regarding the above queries?
A. Both give wrong results.
B. Both give the correct result.
C. Only the first query gives the correct result.
D. Only the second query gives the correct result.
Answer: C
…go to http://www.lead2pass.com/1z0-051.html to download the full version Q&As.
