使用MySQL命令行了解SQL的执行结果

mysql> SELECT title FROM news WHERE id = 1;
+--------------------------------------------+
| title 	 |
+--------------------------------------------+
| Java之父：Oracle对Java未来的重要性被夸大了 	 |
+--------------------------------------------+
1 row in set

mysql> SELECT MAX(id),title FROM news;
+--------------+--------------------------------------------+
| MAX(id) 	 | title 	|
+--------------+--------------------------------------------+
| 179 | Java之父：Oracle对Java未来的重要性被夸大了 	|
+--------------+--------------------------------------------+
1 row in set

mysql> SELECT MAX(id) as 编号,title as 标题 FROM news;
+------+--------------------------------------------+
| 编号 | 标题 |
+------+--------------------------------------------+
| 179 | Java之父：Oracle对Java未来的重要性被夸大了 	|
+------+--------------------------------------------+
1 row in set

mysql> SELECT id AS ID, title as TITLE FROM news WHERE id = (SELECT MAX(id) FROM news);
+-----+----------------------+
| ID | TITLE |
+-----+----------------------+
| 179 | 支付宝会被收归国有？ 	 |
+-----+----------------------+
1 row in set

mysql> SELECT a.title FROM news as a WHERE id = 100;
+-----------------------------+
| title 	 |
+-----------------------------+
| 文化中国传播收购MSN 50%股份 	 |
+-----------------------------+
1 row in set

mysql> SELECT a.title, (SELECT b.tag FROM news as b WHERE id = 100) FROM news as a WHERE id = 100;
+-----------------------------+--------------------------------------------------------+
| title | (SELECT b.tag FROM news as b WHERE id = 100) |
+-----------------------------+--------------------------------------------------------+
| 文化中国传播收购MSN 50%股份 | MSN |
+-----------------------------+--------------------------------------------------------+
1 row in set

mysql> SELECT tag as 标签, SUM(num) as 数量 FROM news GROUP BY tag;
+----------------+------+
| 标签 | 数量 |
+----------------+------+
| adobe | 2 |
| android | 11 |
| apple | 8 |
| apples | 1 |
| Chrome | 2 |
| Firefox | 2 |
| Foxconn | 1 |
| google | 38 |
| Google AdSense | 1 |
| HTML5 | 2 |
| IE6 | 1 |
| intel | 1 |
| java | 1 |
| microsoft | 3 |
| Motorola | 1 |
| MSN | 1 |
| oracle | 3 |
| PHP | 1 |
| QQ | 1 |
| Scala | 1 |
| tencent | 1 |
| VANCL | 1 |
| Windows XP | 1 |
| 乔布斯 | 1 |
| 云计算 | 1 |
| 互联网 | 1 |
| 人人网 | 1 |
| 低碳 | 1 |
| 保罗·艾伦 | 1 |
| 创业 | 1 |
| 创新工场 | 4 |
| 史玉柱 | 1 |
| 唐骏 | 3 |
| 团购 | 1 |
| 域名 | 1 |
| 奇虎360 | 4 |
| 巨人网络 | 1 |
| 年龄歧视 | 2 |
| 广告联盟 | 1 |
| 开心网 | 3 |
| 张朝阳 | 1 |
| 彩虹糖的梦 | 1 |
| 微博 | 1 |
| 微软 | 3 |
| 必应 | 1 |
| 惠普 | 1 |
| 房地产 | 1 |
| 技术类工作 | 1 |
| 招聘 | 1 |
| 探索 | 1 |
| 搜狗 | 1 |
| 搜索 | 1 |
| 支付宝 | 1 |
| 数据中心 | 2 |
| 数据库 | 1 |
| 智力开发 | 1 |
| 暴雪 | 1 |
| 李开复 | 6 |
| 松本行弘 | 1 |
| 比尔·盖茨 | 1 |
| 汽车 | 1 |
| 淘宝网 | 1 |
| 百度 | 1 |
| 硅谷 | 1 |
| 移动开发 | 1 |
| 程序员 | 3 |
| 站长 | 1 |
| 绿坝 | 1 |
| 编程 | 1 |
| 编程语言 | 1 |
| 网游 | 1 |
| 职业规划 | 1 |
| 腾讯 | 5 |
| 腾迅 | 1 |
| 蔡文胜 | 1 |
| 评论 | 3 |
| 诺基亚 | 1 |
| 金山 | 2 |
| 阿里巴巴 | 1 |
| 雷军 | 2 |
| 霍金 | 2 |
| 马云 | 5 |
| 魔兽世界 | 1 |
+----------------+------+
83 rows in set