单选题Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2 (25) LAST_NAME VARCHAR2 (25) HIRE_DATE DATE Which UPDATE statement is valid? （）A UPDATE employees SET first_name = 'John' SET last_name = 'Smith' WHERE emp

第1题：

Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) Which three statements inserts a row into the table? （）

• A、INSERT INTO employees VALUES (NULL, 'JOHN','Smith');
• B、INSERT INTO employees( first_name, last_name) VALUES ('JOHN','Smith');
• C、INSERT INTO employees VALUES ('1000','JOHN','NULL');
• D、INSERT INTO employees(first_name,last_name, employee_id) VALUES ('1000, 'john','Smith');
• E、INSERT INTO employees (employee_id) VALUES (1000);
• F、INSERT INTO employees (employee_id, first_name, last_name) VALUES ( 1000, 'john',");

第2题：

Which three statements inserts a row into the table?（）

• A、INSERT INTO employees   VALUES ( NULL, ‘John’,‘Smith’);
• B、INSERT INTO employees( first_name, last_name)   VALUES(‘John’,‘Smith’);
• C、INSERT INTO employees   VALUES (‘1000’,‘John’,NULL);
• D、INSERT INTO employees(first_name,last_name, employee_id)   VALUES ( 1000, ‘John’,‘Smith’);
• E、INSERT INTO employees (employee_id)   VALUES (1000);
• F、INSERT INTO employees (employee_id, first_name, last_name)   VALUES ( 1000, ‘John’,‘’);

第3题：

Examine the structure of the EMPLOYEES and NEW_EMPLOYEES tables: EMPLOYEES EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2 (25) LAST_NAME VARCHAR2 (25) HIRE_DATE DATE NEW EMPLOYEES EMPLOYEE_ID NUMBER Primary Key NAME 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')'

第4题：

Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) Which three statements insert a row into the table? （）

• A、INSERT INTO employees VALUES (NULL, 'John', 'smith');
• B、INSERT INTO employees (first_name, last_name) VALUES ('John', 'smith');
• C、INSERT INTO employees VALUES ('1000, 'John', 'smith');
• D、INSERT INTO employees (first_name, last_name, employee_id) VALUES (1000, 'John', 'smith');
• E、INSERT INTO employees (employee_id) VALUES (1000);
• F、INSERT INTO employees ( employee_id, first_name, last_name, ) VALUES (1000, 'John','');

第5题：

Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) HIRE_DATE DATE You issue these statements: CREATE table new_emp ( employee_id NUMBER, name VARCHAR2(30)); INSERT INTO new_emp SELECT employee_id , last_name from employees; Savepoint s1; UPDATE new_emp set name = UPPER(name); Savepoint s2; Delete from new_emp; Rollback to s2; Delete from new_emp where employee_id =180; UPDATE new_emp set name = 'James'; Rollback to s2; UPDATE new_emp set name = 'James' WHERE employee_id =180; Rollback; At the end of this transaction, what is true?（）

• A、You have no rows in the table.
• B、You have an employee with the name of James.
• C、You cannot roll back to the same savepoint more than once.
• D、Your last update fails to update any rows because employee ID 180 was already deleted.

第6题：

You own a table called EMPLOYEES with this table structure: EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) HIRE_DATE DATE What happens when you execute this DELETE statement? DELETE employees;（）

• A、You get an error because of a primary key violation.
• B、The data and structure of the EMPLOYEES table are deleted.
• C、The data in the EMPLOYEES table is deleted but not the structure.
• D、You get an error because the statement is not syntactically correct.

第7题：

Examine the description of the EMPLOYEES table: EMP_ID NUMBER(4) NOT NULL LAST_NAME VARCHAR2(30) NOT NULL FIRST_NAME VARCHAR2(30) DEPT_ID NUMBER(2) Which statement produces the number of different departments that have employees with last name Smith?（）

• A、SELECT COUNT(*) FROM employees WHERE last_name='Smith';
• B、SELECT COUNT(dept_id) FROM employees WHERE last_name='Smith';
• C、SELECT DISTINCT(COUNT(dept_id)) FROM employees WHERE last_name='Smith';
• D、SELECT COUNT(DISTINCT dept_id) FROM employees WHERE last_name='Smith';
• E、SELECT UNIQUE(dept_id) FROM employees WHERE last_name='Smith';

第8题：

Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) HIRE_DATE DATE Which INSERT statement is valid?（）

• A、INSERT INTO employees (employee_id, first_name, last_name, hire_date) VALUES (1000, 'John', 'smith','01/01/01);
• B、INSERT INTO employees(employee_id, first_name, last_name, hire_date) VALUES (1000, 'John', 'smith','01 january 01');
• C、INSERT INTO employees(employee_id, first_name, last_name, Hire_date) VALUES (1000, 'John', 'smith', To_ date ('01/01/01));
• D、INSERT INTO employees(employee_id, first_name, last_name, hire_date) VALUES (1000, 'John', 'smith','01-Jan-01');

第9题：

Examine the structure of the EMPLOYEES and NEW_EMPLOYEES tables: EMPLOYEES EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) HIRE_DATE DATE NEW_EMPLOYEES EMPLOYEE_ID NUMBER Primary Key NAME 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 name = 'carrey');

第10题：

Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) HIRE_DATE DATE Which UPDATE statement is valid?（）

• A、UPDATE employees SET first_name = 'John' SET last_name ='Smith' WHERE employee_id = 180;
• B、UPDATE employees SET first_name = 'John', SET last_name ='Smith' WHERE employee_id = 180;
• C、UPDATE employees SET first_name = 'John' AND last_name ='Smith' WHERE employee_id = 180;
• D、UPDATE employees SET first_name = 'John', last_name ='Smith' WHERE employee_id = 180;