找考题网-背景图
单项选择题

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 UNIQE (dept_id) FROM employees WHERE last _name='smith';

<上一题 目录 下一题>
热门试题

单项选择题Which is an iSQL*Plus command? （）

A. INSERT
B. UPDATE
C. SELECT
D. DESCRIBE
E. DELETE
F. RENAME

单项选择题Which SQL statement would you use to remove a view called EMP_DEPT_VU from your schema?（）

A. DROP emp_dept_uv;
B. DELETE emp_dept_uv;
C. REMOVE emp_dept_uv;
D. DROP VIEW emp_dept_uv;
E. DELETE VIEW emp_dept_uv;
F. REMOVE VIEW emp_dept_uv;