多项选择题
A. DELETE employees; B. DESCRIBE employees; C. ROLLBACK TO SAVEPOINT C; D. GRANT SELECT ON employees TO SCOTT; E. ALTER TABLE employees SET UNUSED COLUMN sal; F. Select MAX(sal) FROM employees WHERE department_id = 20;
What is true about sequences?（）A. The start value of th...
单项选择题What is true about sequences?（）
A. The start value of the sequence is always 1. B. A sequence always increments by 1. C. The minimum value of an ascending sequence defaults to 1. D. The maximum value of descending sequence defaults to 1.
The DBA issues this SQL command: What privileges does ...
单项选择题
The DBA issues this SQL command: What privileges does the user Scott have at this point?（）
A. No privileges. B. Only the SELECT privilege. C. Only the CONNECT privilege. D. All the privileges of a default user.
Examine the structure of the EMPLOYEES table: EMPLOYEE_...
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 = 'Smoth' WHERE employee_id = 180; C. UPDATE employee SET first_name = 'John' AND last_name = 'Smith' WHERE employee_id = 180; D. UPDATE employee SET first_name = 'John', last_name = 'Smith' WHERE employee_id = 180;
