2020-02-16 标签:sql,语句,学习指南,查询,结果,显示,a,关键字,select,n,ame,姓名,students,order,age,b,直接

1.在查询结果中显示列名： 　　a.用as关键字：select name as '姓名' from students order by age 　　b.直接表示：select name '姓名' from students order by age 　　2.精确查找: 　　a.用in限定范围：sel