1Z0-007单项选择题每日一练(2019.12.11)

A.DELETE FROM employees WHERE employee_id = (SELECT employee_id FROM employees);
B.DELETE * FROM employees WHERE employee_id = (SELECT employee_id FROM new_employees);
C.DELETE FROM employees WHERE employee_id IN (SELECT employee_id FROM new_employees WHERE name ='Carrey');
D.DELETE * FROM employees WHERE employee_id IN (SELECT employee_id FROM new_employees WHERE last_name ='Carrey');

A. remove the ORDER BY clause
B. remove the table alias prefix from the WHERE clause
C. remove the table alias from the SELECT clause
D. prefix the column in the USING clause with the table alias
E. prefix the column in the ORDER BY clause with the table alias
F. replace the condition "d.department_id NOT IN (10,40)" in the WHERE clause with "d.department_id <> 10 AND d.department_id <> 40"

A. 0
B. 1
C. 0.00
D. An error statement

A. ALTER TABLE students ADD PRIMARY KEY _ 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 ADD CONSTRAINT stud_id_pk PRIMARY KEY (student_id);
E. ALTER TABLE students MODIFY CONSTRAINT stud_id_pk PRIMARY KEY (student_id);

A. Use the DESCRIBE command in the EMP_DEPT VU view.
B. Use the DEFINE VIEW command on the EMP_DEPT VU view.
C. Use the DESCRIBE VIEW command on the EMP_DEPT VU view.
D. Query the USER_VIEWS data dictionary view to search for the EMP_DEPT_VU view.
E. Query the USER_SOURCE data dictionary view to search for the EMP_DEPT_VU view.
F. Query the USER_OBJECTS data dictionary view to search for the EMP_DEPT_VU view.