insert into 表名 [(字段列表)] values (值列表), (值列表)...;
create table my_student(
    id int primary key auto_increment,
    name varchar(10)
);
insert into my_student (name) values ('張三'), ('李四'), ('王五');

mysql> select * from my_student;
+----+--------+
| id | name   |
+----+--------+
|  1 | 張三   |
|  2 | 李四   |
|  3 | 王五   |
+----+--------+

insert into my_student (id, name) values (1, '張飛');
ERROR 1062 (23000): Duplicate entry '1' for key 'PRIMARY'

insert into 表名 [(字段列表)] on duplicate key update 字段=新值;

insert into my_student (id, name) values (1, '張飛') 
on duplicate key update name = '張飛';
mysql> select * from my_student;
+----+--------+
| id | name   |
+----+--------+
|  1 | 張飛   |
|  2 | 李四   |
|  3 | 王五   |
+----+--------+

replace into 表名 [(字段列表)] values (值列表);
replace into  my_student (id, name) values (1, '劉備');
mysql> select * from my_student;
+----+--------+
| id | name   |
+----+--------+
|  1 | 劉備   |
|  2 | 李四   |
|  3 | 王五   |
+----+--------+

insert into 表名 [(字段列表)] select */字段列表 from 表名;
insert into my_student (name) select name from my_student;
mysql> select * from my_student;
+----+--------+
| id | name   |
+----+--------+
|  1 | 劉備   |
|  2 | 李四   |
|  3 | 王五   |
|  4 | 劉備   |
|  5 | 李四   |
|  6 | 王五   |
+----+--------+