I have two tables in my database 

```
create table A1 (username varchar(50), Sn int);
create table A2 (username varchar(50), Sn int);

```

i am inserting the data into table A2

```
insert into A2 values("abhi",1);
insert into A2 values("abhi",2);
insert into A2 values("abhi",3);
insert into A2 values("abhi",4);
insert into A2 values("abhi",5);
insert into A2 values("abhi",,6);

```

After that i have to insert the data from table A2 to A1 in such a way that at the first time row insertion will be from 1 to 3 and at the second time row insertion will be from 4 to 6 

Please help me i am new to Mysql