1Z0-007單項選擇題每日一練(2019.12.11)

單項選擇題
Examine the structure of the EMPLOYEES and NEW_EMPLOYEES tables:EMPLOYEESEMPLOYEE_ID NUMBER Primary KeyFIRST_NAME VARCHAR2(25)LAST_NAME VARCHAR2(25)HIRE_DATE DATENEW_EMPLOYEESEMPLOYEE_ID NUMBER Primary KeyNAME VARCHAR2(60)Which DELETE statement is valid?（）
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');
單項選擇題
Evaluate this SQL statement:SELECT e.emp_name, d.dept_nameFROM employees eJOIN departments dUSING (department_id)WHERE d.department_id NOT IN (10,40)ORSER BY dept_name;The statement fails when executed. Which change fixes the error? （）
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"
單項選擇題
Evaluate the SQL statement:SELECT ROUND(TRUNC(MOD(1600,10),-1),2)FROM dual;What will be displayed? （）
A. 0
B. 1
C. 0.00
D. An error statement
單項選擇題
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 _ 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);
單項選擇題
You need to perform certain data manipulation operations through a view called EMP_DEPT_VU, which you previously created. You want to look at the definition of the view (the SELECT statement on which the view was create.) How do you obtain the definition of the view? （）
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.