http://www.cnblogs.com/wupeiqi/articles/5748496.html 练习题
21 题目着重 看看。。
select 其实相当于 Python 里的print
mysql> select (select count(1 ) from student where gender = ‘男‘) as ‘男‘, (select count(1 ) from student where gender = ‘女‘) as ‘女‘;
+------+------+
| 男 | 女 |
+------+------+
| 10 | 6 |
+------+------+
原文:https://www.cnblogs.com/th-lyc/p/8997835.html