语法:
CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name
[(create_definition,...)]
[table_options] [select_statement]
CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name
[(] LIKE old_tbl_name [)];
测试过程:
原数据表:
mysql> show create table test_order \G
*************************** 1. row ***************************
Table: test_order
Create Table: CREATE TABLE `test_order` (
`pay_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
`origin` int(10) DEFAULT NULL,
`team_id` int(11) DEFAULT NULL,
`state` int(11) DEFAULT NULL,
KEY `team_id` (`team_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8
1 row in set (0.00 sec)
mysql> create table cc select * from test_order;
Query OK, 9900 rows affected (0.11 sec)
Records: 9900 Duplicates: 0 Warnings: 0
mysql> create table dd like test_order;
Query OK, 0 rows affected (0.22 sec)
查看数据:
mysql> select * from cc limit 2;
+---------------------+--------+---------+-------+
| pay_time | origin | team_id | state |
+---------------------+--------+---------+-------+
| 2011-06-22 18:04:47 | 10 | 100 | 100 |
| 2011-06-22 18:04:47 | 10 | 100 | 101 |
+---------------------+--------+---------+-------+
2 rows in set (0.00 sec)
mysql> select * from dd;
Empty set (0.00 sec)
结果:cc表中数据与原表test_order中的一致，dd表中无数据
查看表结构:
mysql> show create table cc \G
*************************** 1. row ***************************
Table: cc
Create Table: CREATE TABLE `cc` (
`pay_time` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
`origin` int(10) DEFAULT NULL,
`team_id` int(11) DEFAULT NULL,
`state` int(11) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8
1 row in set (0.00 sec)
mysql> show create table dd \G
*************************** 1. row ***************************
Table: dd
Create Table: CREATE TABLE `dd` (
`pay_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
`origin` int(10) DEFAULT NULL,
`team_id` int(11) DEFAULT NULL,
`state` int(11) DEFAULT NULL,
KEY `team_id` (`team_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8
1 row in set (0.00 sec)
结果：cc表中，原表中的索引消失了；dd表与原表一致
结论：
create table select 会将原表中的数据完整复制一份，但表结构中的索引会丢失。
create table like 只会完整复制原表的建表语句，但不会复制数据
