摘要：
1. select * from stu where age>20; 2. select * from stu where age>=20; 3. select * from stu where age>=20 and age<=30; 4. select * from stu where hire 阅读全文
摘要：
1. select * from stu order by age asc; 2. select * from stu order by math desc; 3. select * from stu order by math desc,english asc; 阅读全文