MYSQL 临时表与复制表
临时表： 创建后只在当前连接可见，当关闭时 mysql 会自动删除该表。
先BB下临时表的特点： 当使用PHP 来创建MYSQL 临时表，PHP脚本执行完后，临时表会自动销毁。如果是客户端连接 ，则关闭客户端时候关闭临时表。
mysql> CREATE TEMPORARY TABLE SalesSummary (
-> product_name VARCHAR(50) NOT NULL
-> , total_sales DECIMAL(12,2) NOT NULL DEFAULT 0.00
-> , avg_unit_price DECIMAL(7,2) NOT NULL DEFAULT 0.00
-> , total_units_sold INT UNSIGNED NOT NULL DEFAULT 0
);
Query OK, 0 rows affected (0.00 sec)
mysql> INSERT INTO SalesSummary
-> (product_name, total_sales, avg_unit_price, total_units_sold)
-> VALUES
-> ('cucumber', 100.25, 90, 2);
mysql> SELECT * FROM SalesSummary;
+--------------+-------------+----------------+------------------+
| product_name | total_sales | avg_unit_price | total_units_sold |
+--------------+-------------+----------------+------------------+
| cucumber | 100.25 | 90.00 | 2 |
+--------------+-------------+----------------+------------------+
1 row in set (0.00 sec)当使用show tables 命令显示数据表是们无法看到 临时表，
手动删除临时表
mysql> CREATE TEMPORARY TABLE SalesSummary (
-> product_name VARCHAR(50) NOT NULL
-> , total_sales DECIMAL(12,2) NOT NULL DEFAULT 0.00
-> , avg_unit_price DECIMAL(7,2) NOT NULL DEFAULT 0.00
-> , total_units_sold INT UNSIGNED NOT NULL DEFAULT 0
);
Query OK, 0 rows affected (0.00 sec)
mysql> INSERT INTO SalesSummary
-> (product_name, total_sales, avg_unit_price, total_units_sold)
-> VALUES
-> ('cucumber', 100.25, 90, 2);
mysql> SELECT * FROM SalesSummary;
+--------------+-------------+----------------+------------------+
| product_name | total_sales | avg_unit_price | total_units_sold |
+--------------+-------------+----------------+------------------+
| cucumber | 100.25 | 90.00 | 2 |
+--------------+-------------+----------------+------------------+
1 row in set (0.00 sec)
mysql> DROP TABLE SalesSummary;
mysql>SELECT * FROM SalesSummary;
ERROR 1146: Table 'RUNOOB.SalesSummary' doesn't exist
MYSQL 复制表的两种方式：
1.只复制表结构到新表；
create table 新表 select * from 旧表 where 1=2
或者
CREATE TABLE 新表 LIKE 旧表
2.复制表结构及数据到新表：
creat table 新表 select * from 旧表
页:
[1]