多项选择题
Examine the SQL statements that creates ORDERS table: CREATE TABLE orders
(SER_NO NUMBER UNIQUE,
ORDER_ID NUMBER,
ORDER_DATE DATE NOT NULL
STATUS VARCHARD2(10)
CHECK (status IN ('CREDIT','CASH')),
PROD_ID_NUMBER
REFERENCES PRODUCTS(PRODUCT_ID),
ORD_TOTAL NUMBER,
PRIMARY KEY (order id, order date));
For which columns would an index be automatically created when you execute the aboveSQL statement? （）
A. SER_NO
B. ORDER_ID
C. STATUS
D. PROD_ID
E. ORD_TOTAL
F. Composite index on ORDER_ID and ORDER_DATE
相关考题
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单项选择题
Which statement explicitly names a constraint? （）
A. ALTER TABLE student_grades ADD FOREIGN KEY (student_id) REFERENCES students (student_id);
B. ALTER TABLE student_grades ADD CONSTRAINT NAME = student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id);
C. ALTER TABLE student_grades ADD CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id);
D. ALTER TABLE student grades ADD NAMED CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id);
E. ALTER TABLE student grades ADD NAME student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id); -
单项选择题
You want to display the titles of books that meet these criteria: 1. Purchased before January 21, 2001 2. Price is less then $500 or greater than $900 You want to sort the results by their data of purchase, starting with the most recently bought book. Which statement should you use? （）
A. SELECT book_title FROM books WHERE price between 500 and 900 AND purchase_date < '21-JAN-2001' ORDER BY purchase_date;
B. SELECT book_title FROM books WHERE price IN (500,900) AND purchase_date < '21-JAN-2001' ORDER BY purchase date ASC;
C. SELECT book_title FROM books WHERE price < 500 or > 900 AND purchase_date < '21-JAN-2001' ORDER BY purchase date DESC;
D. SELECT book_title FROM books WHERE (price < 500 OR price > 900) AND purchase_date < '21-JAN-2001' ORDER BY purchase date DESC; -
单项选择题
Which /SQL*Plus feature can be used to replace values in the WHERE clause?（）
A. Substitution variables
B. Replacement variables
C. Prompt variables
D. Instead-of variables
E. This feature cannot be implemented through /SQL*Plus.
