Restart auto-increment on the next value of the another column

Question

I want to make it in such a way that I get:

Main | Column I want to reset on new main value

 1 | 100 1 | 101 1 | 102 1 | 103 1 | 104 2 | 100 2 | 101 

Answer 1

You can use MyIsam engine to achieve this -

CREATE TABLE table1(
  id1 INT(11) NOT NULL,
  id2 INT(11) NOT NULL AUTO_INCREMENT,
  PRIMARY KEY (id1, id2)
);

INSERT INTO table1 VALUES (1, NULL);
INSERT INTO table1 VALUES (1, NULL);
INSERT INTO table1 VALUES (2, NULL);
INSERT INTO table1 VALUES (2, NULL);

SELECT * FROM table1;
+-----+-----+
| id1 | id2 |
+-----+-----+
|   1 |   1 |
|   1 |   2 |
|   2 |   1 |
|   2 |   2 |
+-----+-----+