Mysql 视图创建语句中不能使用union吗? 本帖最后由 onunix 于 2012-04-06 18:37:17 编辑 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 用union是有原则的,select * from InformalBudget_1 与select * from InformalBudget列数是否相同数据类型是否一致,如果列数和数据类型都不一致的话,肯定会报错的。 mysql> select * from device;+--------+------------+| dev_id | power_stat |+--------+------------+| 1 | 319 || 3 | 415 || 4 | 415 || 5 | 255 || 7 | 0 || 8 | 415 || 9 | 0 || 10 | 0 || 11 | 0 |+--------+------------+9 rows in set (0.07 sec)mysql> create view InformalBudgetUnion as -> select * from device union all select * from device;Query OK, 0 rows affected (0.07 sec)mysql> select * from InformalBudgetUnion;+--------+------------+| dev_id | power_stat |+--------+------------+| 1 | 319 || 3 | 415 || 4 | 415 || 5 | 255 || 7 | 0 || 8 | 415 || 9 | 0 || 10 | 0 || 11 | 0 || 1 | 319 || 3 | 415 || 4 | 415 || 5 | 255 || 7 | 0 || 8 | 415 || 9 | 0 || 10 | 0 || 11 | 0 |+--------+------------+18 rows in set (0.00 sec)mysql> select version();+------------------+| version() |+------------------+| 5.1.58-community |+------------------+1 row in set (0.00 sec)mysql> 数据表中的索引id如何重置? 求助各位大哥,知道哪里有Progress数据库的中文资料吗?(最后40分了) 请问一个数据库设计问题,希望能保证一致性的同时,保证查询速度 C语言重复调用存储过程出错 关于linux下直接拷贝myisam类型表备份的问题!!急~~~~~ 一个令人十分不解的问题,请大家帮个忙 MySQL目前似乎没有中文问题的组合 创建存储过程失败,求大神指导 帮忙看看这样的查询怎么实现,谢谢 有关用c语言编写mysql的应用程序遇到的问题,求教 两个mysql服务器之间如何高效的倒数据?? 初学者关于官方Mysql的疑问!!!
列数是否相同数据类型是否一致,如果列数和数据类型都不一致的话,肯定会报错的。
+--------+------------+
| dev_id | power_stat |
+--------+------------+
| 1 | 319 |
| 3 | 415 |
| 4 | 415 |
| 5 | 255 |
| 7 | 0 |
| 8 | 415 |
| 9 | 0 |
| 10 | 0 |
| 11 | 0 |
+--------+------------+
9 rows in set (0.07 sec)mysql> create view InformalBudgetUnion as
-> select * from device union all select * from device;
Query OK, 0 rows affected (0.07 sec)mysql> select * from InformalBudgetUnion;
+--------+------------+
| dev_id | power_stat |
+--------+------------+
| 1 | 319 |
| 3 | 415 |
| 4 | 415 |
| 5 | 255 |
| 7 | 0 |
| 8 | 415 |
| 9 | 0 |
| 10 | 0 |
| 11 | 0 |
| 1 | 319 |
| 3 | 415 |
| 4 | 415 |
| 5 | 255 |
| 7 | 0 |
| 8 | 415 |
| 9 | 0 |
| 10 | 0 |
| 11 | 0 |
+--------+------------+
18 rows in set (0.00 sec)mysql> select version();
+------------------+
| version() |
+------------------+
| 5.1.58-community |
+------------------+
1 row in set (0.00 sec)mysql>