本文为本人学习书籍《MySQL必知必会》笔记系列，欢迎收藏学习，有问题随时留言评论，一起探讨。

第四章 检索数据

#单个列查询
SELECT user.id FROM weibo.user;
#多个列查询
SELECT user.screen_name,user.gender,user.follow_count,followers_count
FROM weibo.user;
#输出起始位置为0后的5行
SELECT user.screen_name FROM weibo.user
LIMIT 0,5;
#使用完全限定的表名
SELECT user.gender FROM weibo.user;
SELECT DISTINCT user.gender FROM weibo.user;

第五章 排序检索

#单个列排序检索：按照screen_name的字母顺序排列
SELECT user.screen_name 
FROM weibo.user
ORDER BY user.screen_name;
#多个列排序检索
SELECT user.screen_name,user.gender,user.follow_count,followers_count
FROM weibo.user
ORDER BY user.follow_count,followers_count;
#单个列降序：followers_count
SELECT user.screen_name,user.gender,user.follow_count,followers_count
FROM weibo.user
ORDER BY user.followers_count DESC;
#多个列降序
SELECT user.screen_name,user.gender,user.follow_count,followers_count
FROM weibo.user
ORDER BY user.follow_count DESC,user.followers_count DESC;
#ORDER BY和LIMIT组合找到最大/小值
SELECT user.screen_name,user.gender,user.follow_count,followers_count
FROM weibo.user
ORDER BY user.followers_count DESC
LIMIT 1;