📄 rel-ops.txt.txt
字号:
SELECT Title, Price
FROM BOOK a, PUBLISHER b
WHERE a.PublisherID = b.PublisherID
AND (b.Pname = '清华大学出版社' OR b.Pname='电子工业出版社');
Relational operations:
SELECT, FROM, WHERE, AND, OR
SELECT A FROM B 指从表B中选出属性A,并具备条件S
WHERE连接条件S,S用AND和OR连接。
SELECT Pname
FROM BOOK a, PUBLISHER b
WHERE Title = 'Big C++' AND a.PublisherID = b.PublisherID;
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