rel-ops.txt

来自「SSD7 exercise 1 参考答案」· 文本 代码 · 共 6 行

SELECT Title, Price FROM BOOK WHERE PublisherID IN 
(SELECT PublisherID FROM PUBLISHER WHERE Name = 'Prentice Hall' OR Name = 'Atros');

The "SELECT" relational operation was used to get some specific rows in a table.
IN the above SQL commands, the "SELECT" operation was used to get the PublisherID corresponding to the Publisher named 'Prentice Hall' or 'Atros'.
Also it is used to get the Title and  Price of some recond  corresponding to the the selected publisher ID.