---------------compute子句
select orderid,goodsname,customerid,ordersum from orders where orderdate>'2007/4/18' compute sum(ordersum)
-------查询在年月日之后的订单的金额，并统计总金额。
select emp_id, emp_name, base_salary,price from emp where start_time>'1999/01/01' compute sum(base_salary)
---查询在年月日入职员工的基本工资，并且对这些员工的基本工资进行统计。
select orderid,goodsname,customerid,ordersum from orders where orderdate>'2007/4/18' order by goodsnamecompute sum(ordersum) by goodsname
----查询在年月日之后的订单的金额，并统计每种货品的订单总金额。若使用COMPUTE BY ,则必须使用ORDER BY 。
select student_name as '姓名',min(age) as '最小年龄',max(age) as '最大年龄' from student where sex=0 group by student_name
---查询students表中最小年龄和最大年龄的女生。
select min(age) as '最小年龄',max(age) as '最大年龄',sex from student group by sex having sex=0
---查询students表中最小年龄和最大年龄的女生
----------------内连接查询
select student_id,student_name,class_name from student inner join class_info on student.class_id=class_info.class_id
----显示学生的信息，并且显示学生所属的班级名称
select student_id,student_name,class_name from student inner join class_info on student.class_id=class_info.class_id where student.class_id in ('g9901','g9902') order by class_info.class_name desc
---------显示网页一班和网页二班的学生编号及姓名，并显示学生所属班级名称，按班级名称进行降序显示。
select emp.emp_id,emp_name,start_time,class_name from emp inner join teaching on emp.emp_id=teaching.emp_id
-----------显示雇员表中每个老师的入职时间和姓名以及所对应教学的课程。
select student_id,student_name,class_name
from student
inner join class_info
on student.class_id=class_info.class_id
--------查询学生表中按照班级显示学生姓名以及student_id
select student.student_id,student_name,coursename,class_name,grade
from student
inner join class_info
on student.class_id=class_info.class_id
inner join student_course
on student.student_id=student_course.student_id
inner join course
on course.courseid=student_course.course_id
where class_name in ('网页一班','网页二班')
order by student.class_id
---------查询student表中网页一班和网页二班按照学生姓名以及student_id和所参加考试的科目以及考试成绩。
本文转自 沐小七 51CTO博客，原文链接:http://blog.51cto.com/3088522/566621
