mysql 数据插入insert

mysql> select * from user;
+------+----------+-----------+
| id   | name     | address   |
+------+----------+-----------+
|    1 | xiaoming | beijing   |
|    2 | xiaobai  | shandong  |
|    3 | xiaohong | suzhou    |
|    4 | xiaohei  | changchun |
+------+----------+-----------+
4 rows in set (0.00 sec)


mysql> insert user(id,name,address) values(5,"xiaoli","dongjing"),(6,"xiaohuang","meiguo");
Query OK, 2 rows affected (0.01 sec)
Records: 2  Duplicates: 0  Warnings: 0


mysql> insert user(id,name,address) select id,name,address from user where id=1;
Query OK, 1 row affected (0.01 sec)
Records: 1  Duplicates: 0  Warnings: 0


mysql> select * from user;
+------+-----------+-----------+
| id   | name      | address   |
+------+-----------+-----------+
|    1 | xiaoming  | beijing   |
|    2 | xiaobai   | shandong  |
|    3 | xiaohong  | suzhou    |
|    4 | xiaohei   | changchun |
|    5 | xiaoli    | dongjing  |
|    6 | xiaohuang | meiguo    |
|    1 | xiaoming  | beijing   |
+------+-----------+-----------+
7 rows in set (0.00 sec)

mysql> insert into user(id,name,address) select id,name,address from user where id=1;
Query OK, 2 rows affected (0.01 sec)
Records: 2  Duplicates: 0  Warnings: 0


mysql> select * from user;
+------+-----------+-----------+
| id   | name      | address   |
+------+-----------+-----------+
|    1 | xiaoming  | beijing   |
|    2 | xiaobai   | shandong  |
|    3 | xiaohong  | suzhou    |
|    4 | xiaohei   | changchun |
|    5 | xiaoli    | dongjing  |
|    6 | xiaohuang | meiguo    |
|    1 | xiaoming  | beijing   |
|    1 | xiaoming  | beijing   |
|    1 | xiaoming  | beijing   |
+------+-----------+-----------+
9 rows in set (0.00 sec)