摘要：
基本常用查询--selectselect * from student; --all 查询所有select all sex from student; --distinct 过滤重复select distinct sex from student; --count 统计select count(*) from student;select count(sex) from student;select count(distinct sex) from student; --top 取前N条记录select top 3 * from student; --alias column name 列重命 阅读全文