rel-ops.txt

ssd7的练习一

3.
SELECT BOOK.Title,BOOK.Price
FROM BOOK,PUBLISHER
WHERE BOOK.PublisherID=PUBLISHER.PublisherID 
	AND (PUBLISHER.Name='China Machine Press' OR PUBLISHER.Name='Wenhui Publishing House'); 


AS title and price belong to the BOOK table, but the searching conditions are in the PUBLISHER table. 
Select Title and Price refered to PublisherID,which are selected from PUBLISHER TABLE where the Publisher's name equals "China Machine Press", from  the BOOK TABLE.


4.
SELECT PUBLISHER.Name
FROM PUBLISHER,BOOK
WHERE BOOK.PublisherID=PUBLISHER.PublisherID
	AND BOOK.Title='Thingking in C++';