单项选择题X 纠错
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.
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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);
单项选择题
A. USER_TAB_PRIVS_MADE
B. USER_TAB_PRIVS
C. USER_COL_PRIVS_MADE
D. USER_COL_PRIVS
单项选择题
A. The statement produces an error at line 1.
B. The statement produces an error at line 3.
C. The statement produces an error at line 6.
D. The statement returns the employee name, salary, department ID, and maximum salary earned in the department of the employee for all departments that pay less salary then the maximum salary paid in the company.
E. The statement returns the employee name, salary, department ID, and maximum salary earned in the department of the employee for all employees who earn less than the maximum salary in their department.
单项选择题
A. The DESCRIBE DEPT statement displays the structure of the DEPT table.
B. The ROLLBACK statement frees the storage space occupies by the DEPT table.
C. The DESCRIBE DEPT statement returns an error ORA-04043: object DEPT does not exist.
D. The DESCRIBE DEPT statement displays the structure of the DEPT table only if there is a COMMIT statement introduced before the ROLLBACK statement.