單項(xiàng)選擇題

You need to modify the STUDENTS table to add a primary key on the STUDENT_ID column. The table is currently empty.Which statement accomplishes this task?（）

A. ALTER TABLE students ADD PRIMARY KEY student_id;
B. ALTER TABLE students ADD CONSTRAINT PRIMARY KEY (student _ id);
C. ALTER TABLE students ADD CONSTRAINT stud _ id _pk PRIMARY KEY (student _ id);
D. ALTER TABLE students MODIFY CONSTRAINT stud _ id _pk PRIMARY KEY (student _ id);

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單項(xiàng)選擇題

The EMPLOYEE tables has these columns:

You want to display the name and annual salary multiplied by the commission_pct for all employees. For records that have a NULL commission_pct, a zero must be displayed against the calculated column.
Which SQL statement displays the desired results?（）

A. SELECT last_name, (salary * 12) * commission_pct   FROM EMPLOYEES;
B. SELECT last_name, (salary * 12) * IFNULL(commission_pct, 0)   FROM EMPLOYEES;
C. SELECT last_name, (salary * 12) * NVL2(commission_pct, 0)   FROM EMPLOYEES;
D. SELECT last_name, (salary * 12) * NVL(commission_pct, 0)   FROM EMPLOYEES;

單項(xiàng)選擇題

Examine the data from the ORDERS and CUSTOMERS table.
ORDERS
ORD_ID ORD_DATE CUST_ID ORD_TOTAL
100 12-JAN-2000 15 10000
09-MAR-
101 40 8000
09-MAR-
102 35 12500
15-MAR-
103 15 12000
104 25-JUN-2000 15 6000
105 18-JUL-2000 20 5000
106 18-JUL-2000 35 7000
107 21-JUL-2000 20 6500
04-AUG-
108 10 8000
CUSTOMERS
CUST_ID CUST_NAME CITY
10 Smith Los Angeles
15 Bob San Francisco
20 Martin Chicago
25 Mary New York
30 Rina Chicago
35 Smith New York
40 Linda New York
Which SQL statement retrieves the order ID, customer ID, and order total for the orders that are placed on the same day that Martin places his orders?（）

A. SELECT ord_id, cust_id, ord_total FROM orders, customers WHERE cust_name='Mating' AND ord _ date IN ('18-JUL-2000','21-JUL-2000');
B. SELECT ord_id, cust_id, ord_total FROM orders Where ord_date IN (SELECT ord_date FROM orders WHERE cust_id = (SELECT cust_id FROM customers WHERE cust_name = 'MARTIN'));
C. SELECT ord_id, cust_id, ord_total FROM orders Where ord_date IN (SELECT ord_date FROM orders, customers Where cust _ name = 'Martin');
D. SELECT ord_id, cust_id, ord_total FROM orders WHERE cust_id IN (SELECT cust_id FROM customers WHERE cust name = 'Martin');

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You need to modify the STUDENTS table to add a primary key on the STUDENT_ID column. The table is currently empty.Which statement accomplishes this task?（）

你可能感興趣的試題

The EMPLOYEE tables has these columns: You want to display the name and annual salary multiplied by the commission_pct for all employees. For records that have a NULL commission_pct, a zero must be displayed against the calculated column. Which SQL statement displays the desired results?（）

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The EMPLOYEE tables has these columns:

You want to display the name and annual salary multiplied by the commission_pct for all employees. For records that have a NULL commission_pct, a zero must be displayed against the calculated column.
Which SQL statement displays the desired results?（）