如何自動增加mysql編號

Question

我想增加6的id，意味着當下一個entery進入然後8，然後再輸入14這樣一個。怎麼做。

    +--------------------------+-------+ 
       | username    | user_id | 
       +--------------------------+-------+ 
       | yanki     | 1  | 
       | dude      | 2  | 
       +--------------------------+-------+ 

Answer 1

檢查auto_increment_increment，從文檔：

mysql> SHOW VARIABLES LIKE 'auto_inc%'; 
+--------------------------+-------+ 
| Variable_name   | Value | 
+--------------------------+-------+ 
| auto_increment_increment | 1  | 
| auto_increment_offset | 1  | 
+--------------------------+-------+ 
2 rows in set (0.00 sec) 

mysql> CREATE TABLE autoinc1 
    -> (col INT NOT NULL AUTO_INCREMENT PRIMARY KEY); 
    Query OK, 0 rows affected (0.04 sec) 

mysql> SET @@auto_increment_increment=10; 
Query OK, 0 rows affected (0.00 sec) 

mysql> SHOW VARIABLES LIKE 'auto_inc%'; 
+--------------------------+-------+ 
| Variable_name   | Value | 
+--------------------------+-------+ 
| auto_increment_increment | 10 | 
| auto_increment_offset | 1  | 
+--------------------------+-------+ 
2 rows in set (0.01 sec) 

mysql> INSERT INTO autoinc1 VALUES (NULL), (NULL), (NULL), (NULL); 
Query OK, 4 rows affected (0.00 sec) 
Records: 4 Duplicates: 0 Warnings: 0 

mysql> SELECT col FROM autoinc1; 
+-----+ 
| col | 
+-----+ 
| 1 | 
| 11 | 
| 21 | 
| 31 | 
+-----+ 
4 rows in set (0.00 sec) 

請記住，這是每個數據庫不是每個表。

不可能將這兩個變量的影響限制在一個表中;