[简单及连接查询.pptVIP

查询Booksys表中作者名为_志明的图书 名称和出版日期。 use bookborrow go select bname,publicationdate from Booksys where author like _志明 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 查询Booksys表中出版社名包含人民的图书名称、图书类别和出版社。 use bookborrow go select bname,category,press from Booksys where press like [人、民]% Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 查询Booksys表中出版社名不包含人民的图书名称、图书类别和出版社。 use bookborrow go select bname,category,press from Booksys where press like [^人、民]% Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 排序查询 使用ORDER BY子句可以按一个或多个属性列对数据进行排序，排序方式有升序（ASC）和降序（DESC）2种，默认的排序方式为升序。 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 查询Booksys表中的图书编号、图书名称 和图书价格，图书价格按照升序排列。 use bookborrow go select bno,bname,price from Booksys order by price Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 注意：当排序列中包含空值（NULL） 时，NULL将被视为最大值来处理。 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 分组查询 使用GROUP BY子句可以根据某列的值对查询结果进行分组，然后再进行统计和汇总。 如果未对查询结果分组，聚集函数将作用于整个查询结果。如果对查询结果分组，聚集函数将分别作用于每个组。 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 例：如要查询每个同学的所有课程总分，可将成绩表中的行按照学号分组，即学号相同的行分成一组（一个组就是一个同学的成绩清单），然后用聚合函数对每个组的成绩列求和，即可求出每个学生的课程总分。 use StudentElective go select cno as 课程编号，avg(degree) as 平均成绩 from Elective group by cno Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 如果分组后，还要求按一定的条件对这些组进行筛选，可以使用HAVING子句指定筛选条件，最终只输出满足指定筛选条件的组。 HAVING子句必须与GROUP BY子句同时出现，并且必须出现在GROUP BY子句之后。 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.