INSERT INTO SELECT 语句
发表于 2018-3-6 14:49:52 | 分类于 SQL |
INSERT INTO SELECT 语句
INSERT INTO SELECT 语句从一个表复制数据,然后把数据插入到一个已存在的表中。目标表中任何已存在的行都不会受影响。
语法
从一个表中复制所有的列插入到另一个已存在的表中:
INSERT INTO table2
SELECT * FROM table1;
或者只复制希望的列插入到另一个已存在的表中:
INSERT INTO table2
(column_name(s))
SELECT column_name(s)
FROM table1;
示例
示例使用样本数据库。
"Websites" 表的数据:
+----+--------------+---------------------------+-------+---------+
| id | name | url | alexa | country |
+----+--------------+---------------------------+-------+---------+
| 1 | Google | https://www.google.cm/ | 1 | USA |
| 2 | 淘宝 | https://www.taobao.com/ | 13 | CN |
| 3 | 菜鸟教程 | http://www.runoob.com/ | 4689 | CN |
| 4 | 微博 | http://weibo.com/ | 20 | CN |
| 5 | Facebook | https://www.facebook.com/ | 3 | USA |
| 7 | stackoverflow | http://stackoverflow.com/ | 0 | IND |
+----+---------------+---------------------------+-------+---------+
"apps" 表 的数据:
mysql> SELECT * FROM apps;
+----+------------+-------------------------+---------+
| id | app_name | url | country |
+----+------------+-------------------------+---------+
| 1 | QQ APP | http://im.qq.com/ | CN |
| 2 | 微博 APP | http://weibo.com/ | CN |
| 3 | 淘宝 APP | https://www.taobao.com/ | CN |
+----+------------+-------------------------+---------+
INSERT INTO SELECT 示例
复制 "apps" 中的数据插入到 "Websites" 中:
INSERT INTO Websites (name, country)
SELECT app_name, country FROM apps;
只复制 QQ 的 APP 到 "Websites" 中:
INSERT INTO Websites (name, country)
SELECT app_name, country FROM apps
WHERE id=1;