create table student(
eid int(11) auto_increment  primary key ,
ename varchar(40),
sex varchar(10),
tel varchar(50),
class_id int(11) ,
age int(11),
sal int(2)
)


insert into student(ename,sex,tel,class_id,age,sal) values
 ('小红','女','16738192312','1','25','3000'),
 ('小蓝','男','17863123412','2','10','1000'),
 ('小绿','女','16234231124','2','25','2000'),
 ('小黄','男','16867454532','1','25','8000')
 
 
 insert into student(ename,sex,tel,class_id,age,sal) values
 ('小博','男','17639414630','1','50','10000')
 
 
 
 #2.查询所有学生信息，并根据年龄进行降序排序。（10分）
 
SELECT
	* 
FROM
	student
	LEFT JOIN class ON class.class_id = student.class_id 
ORDER BY
	student.age DESC
 
 
 #3.显示姓王的学生的详细信息。（10分）
SELECT
	* 
FROM
	student
	LEFT JOIN class ON class.class_id = student.class_id 
	where student.ename like ('%王%')
 
 
 #4.查询工资大于5000的所有男同学的信息。（10分）
 
 SELECT
	* 
FROM
	student
	LEFT JOIN class ON class.class_id = student.class_id 
	where student.sal > 5000
	
	#5.查询班级编号为20的男同学的电话号码。（10分）
  SELECT
	student.tel 
FROM
	student
	LEFT JOIN class ON class.class_id = student.class_id 
	where student.class_id = 20
  and student.sex = '男'
 
 
 
#6.查询最低工资。（10分）
SELECT
	student.sal 
FROM
	student 
ORDER BY
	student.sal 
	LIMIT 1

#7.查询班级为30的学生的最小年龄。（10分）

  SELECT
	*
FROM
	student
	LEFT JOIN class ON class.class_id = student.class_id 
	where student.class_id = 20 
	ORDER BY student.age limit 1
	
	
	#8.查询女生的最低工资。（15分）
	
SELECT
	student.sal
FROM
	student
	LEFT JOIN class ON class.class_id = student.class_id 
	where student.sex = '女' ORDER BY student.sal limit 1
	
	#9.查询女学生中薪资最低的人的全部信息。（15分）
	
SELECT
	*
FROM
	student
	LEFT JOIN class ON class.class_id = student.class_id 
	where student.sex = '女' ORDER BY student.sal limit 1