单项选择题X 纠错
A. ALTER VIEW EMP_dept_vu (ADD manger_id NUMBER);
B. MODIFY VIEW EMP_dept_vu (ADD manger_id NUMBER);
C. ALTER VIEW emp_dept_vu AS SELECT employee_id, employee_name, department_name, manager_id FROM employee e, departments d WHERE e.department _ id = d.department_id;
D. MODIFY VIEW emp_dept_vu AS SELECT employee_id, employee_name, department_name, manager_id FROM employees e, departments d WHERE e.department _ id = d.department_id;
E. CREATE OR REPLACE VIEW emp_dept_vu AS SELECT employee_id, employee_name, department_name, manager_id FROM employees e, departments d WHERE e.department _ id = d.department_id;
F. You must remove the existing view first, and then run the CREATE VIEW command with a new column list to modify a view.
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多项选择题
A. SER_NO
B. ORDER_ID
C. STATUS
D. PROD_ID
E. ORD_TOTAL
F. Composite index on ORDER_ID and ORDER_DATE
多项选择题
A. TIMESTAMP
B. INTERVAL MONTH TO DAY
C. INTERVAL DAY TO SECOND
D. INTERVAL YEAR TO MONTH
E. TIMESTAMP WITH DATABASE TIMEZONE
单项选择题
A. Only the row with department ID 40 is deleted in the DEPARTMENTS table.
B. The statement fails because there are child records in the EMPLOYEES table with department ID 40.
C. The row with department ID 40 is deleted in the DEPARTMENTS table. Also the rows with employee IDs 110 and 106 are deleted from the EMPLOYEES table.
D. The row with department ID 40 is deleted in the DEPARTMENTS table. Also the rows with employee IDs 106 and 110 and the employees working under employee 110 are deleted from the EMPLOYEES table.
E. The row with department ID 40 is deleted in the DEPARTMENTS table. Also all the rows in the EMPLOYEES table are deleted.
F. The statement fails because there are no columns specifies in the DELETE clause of the DELETE statement.
单项选择题
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
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
A. Substitution variables
B. Replacement variables
C. Prompt variables
D. Instead-of variables
E. This feature cannot be implemented through /SQL*Plus.
单项选择题
A. The statement executes successfully and returns the student ID and sum of all marks for each student who obtained more than the average mark in each subject.
B. The statement returns an error at the SELECT clause.
C. The statement returns an error at the WHERE clause.
D. The statement returns an error at the ORDER BY clause.
单项选择题
A. 0
B. 1
C. 0.00
D. An error statement
单项选择题
A. The SQL statement displays the desired results.
B. The column in the WHERE clause should be changed to display the desired results.
C. The operator in the WHERE clause should be changed to display the desired results.
D. The WHERE clause should be changed to use an outer join to display the desired results.
单项选择题
A. SELECT employee_id, department_id, department_name, salary FROM employees WHERE department_id IN (SELECT department_id FROM departments);
B. SELECT employee_id, department_id, department_name, salary FROM employees NATURAL JOIN departments;
C. SELECT employee_id, d.department_id, department_name, salary FROM employees e JOIN departments d ON e.department _ id = d. department_id;
D. SELECT employee_id, department_id, department_name, Salary FROM employees JOIN departments USING (e.department_id, d.department_id);