More Related Content
Similar to メッチャ役に立つauto_incrementの話 (9)
メッチャ役に立つauto_incrementの話
- 6. 普通にINSERT
+---------+-----------+
| user_id | user_name |
+---------+-----------+
| 1 | user01 |
| 2 | user02 |
| 3 | user03 |
+---------+-----------+
3 rows in set (0.00 sec)
- 7. user_id=2をDELETE
+---------+-----------+
| user_id | user_name |
+---------+-----------+
| 1 | user01 |
| ! 2 | user02 |
| 3 | user03 |
+---------+-----------+
3 rows in set (0.00 sec)
- 8. この状態で新規行をINSERT
+---------+-----------+
| user_id | user_name |
+---------+-----------+
| 1 | user01 |
| 3 | user03 |
+---------+-----------+
2 rows in set (0.00 sec)
- 9. 最後に追加された
+---------+-----------+
| user_id | user_name |
+---------+-----------+
| 1 | user01 |
| 3 | user03 |
| ! 4 | userXX |
+---------+-----------+
3 rows in set (0.00 sec)
- 10. 最後の行をDELETEしてINSERTすると?
+---------+-----------+
| user_id | user_name |
+---------+-----------+
| 1 | user01 |
| 3 | user03 |
| ! 4 | userXX |
+---------+-----------+
3 rows in set (0.00 sec)
- 11. 最後に追加された
+---------+-----------+
| user_id | user_name |
+---------+-----------+
| 1 | user01 |
| 3 | user03 |
| ! 5 | userYY |
+---------+-----------+
3 rows in set (0.00 sec)
- 14. ここに新規行をINSERT
+---------+-----------+
| user_id | user_name |
+---------+-----------+
| 1 | user01 |
| 3 | user03 |
| 4 | userXX |
| 5 | userYY |
| 10 | user10 |
+---------+-----------+
- 17. 指定場所に追加される
+---------+-----------+
| user_id | user_name |
+---------+-----------+
| 1 | user01 |
| ! 2 | user02 |
| 3 | user03 |
| 4 | userXX |
| 5 | userYY |
| 10 | user10 |
| 11 | userZZ |
- 27. 今のシーケンス値を知る方法
SHOW CREATE TABLE tbl;
+-------+------------------------------------------------+
| Table | Create Table |
+-------+------------------------------------------------+
| tbl | CREATE TABLE `tbl` ( |
| | `user_id` tinyint(4) NOT NULL AUTO_INCREMENT, |
| | `user_name` char(10) DEFAULT NULL, |
| | PRIMARY KEY (`user_id`) |
| | ) ENGINE=InnoDB AUTO_INCREMENT=10 |
+-------+------------------------------------------------+
- 29. 複合キーでauto_increment
insert into tbl(dept_id, user_name) values(1, 'aa');
insert into tbl(dept_id, user_name) values(1, 'bb');
insert into tbl(dept_id, user_name) values(1, 'cc');
insert into tbl(dept_id, user_name) values(2, 'aa');
insert into tbl(dept_id, user_name) values(2, 'bb');
insert into tbl(dept_id, user_name) values(2, 'cc');
1と2の部門に3件ずつINSERTしてみる
Editor's Notes
- \n
- \n
- \n
- \n
- \n
- \n
- \n
- \n
- \n
- \n
- \n
- \n
- \n
- \n
- \n
- \n
- \n
- \n
- \n
- \n
- \n
- \n
- \n
- \n
- \n
- \n
- \n
- \n
- \n
- \n
- \n
- \n