| Question for this problem [message #138230] |
Tue, 20 September 2005 16:20 |
liuyanhong1
Messages: 3
Registered: September 2005
|
Junior Member |
|
|
Hi,
Can some SQL experts solve the following problem:
DEPARTMENTS
DEPARTMENT_ID NUMBER NOT NULL, Primary Key
DEPARTMENT_NAME VARCHAR2
(30)
MGR_ID NUMBER References NGR_ID column of the
EMPLOYEES table
LOCATION_ID NUMBER Foreign key to LOCATION_ID column of the
LOCATIONS table
LOCATIONS
LOCATION_ID NUMBER NOT NULL, Primary Key
CITY VARCHAR2 |30)
Which two SQL statements produce the name, department name, and the city of all the
employees who earn more then 10000? (Choose two)
A. SELECT emp_name, department_name, city
FROM employees e
JOIN departments d
USING (department_id)
JOIN locations 1
USING (location_id)
WHERE salary > 10000;
B. SELECT emp_name, department_name, city
FROM employees e, departments d, locations 1
JOIN ON (e.department_id = d.department id)
AND (d.location_id =1.location_id)
AND salary > 10000;
C. SELECT emp_name, department_name, city
FROM employees e, departments d, locations 1
WHERE salary > 10000;
D. SELECT emp_name, department_name, city
FROM employees e, departments d, locations 1
WHERE e.department_id = d.department_id
AND d.location_id = 1.location_id
AND salary > 10000;
E. SELECT emp_name, department_name, city
FROM employees e
NATURAL JOIN departments, locations
WHERE salary > 10000;
Answer given: B, D
But I think B could be wrong. How can one join used in more than 2 tables. I choose A, D.
Please tell me which one is right. If B is right, could you tell me which site can find the proof. Thanks in advance!
|
|
|
|
] 
Blog
Search
Help
Members
Register
Login
Home
