----------+
17. | Level | Code | Message |
18. +---------+------+------------------+
19. | Warning | 1329 | No data to FETCH |
20. +---------+------+------------------+
21. 1 row in set (0.00 sec)
mysql> SELECT currval('MovieSeq');
+---------------------+
| currval('MovieSeq') |
+---------------------+
| 3 |
+---------------------+
1 row in set (0.00 sec)
mysql> SELECT currval('x');
+--------------+
| currval('x') |
+--------------+
| 0 |
+--------------+
1 row in set, 1 warning (0.00 sec)
mysql> show warnings;
+---------+------+------------------+
| Level | Code | Message |
+---------+------+------------------+
| Warning | 1329 | No data to FETCH |
+---------+------+------------------+
1 row in set (0.00 sec)
nextval
Java代码
1. DROP FUNCTION IF EXISTS nextval;
2. DELIMITER $
3. CREATE FUNCTION nextval (seq_name VARCHAR(50))
4. RETURNS INTEGER
5. CONTAINS SQL
6. BEGIN
7. UPDATE sequence
8. SET current_value = current_value + increment
9. WHERE name = seq_name;
10. RETURN currval(seq_name);
11. END$
12. DELIMITER ;
Java代码
1. mysql> select nextval('MovieSeq');
2. +---------------------+
3. | nextval('MovieSeq') |
4. +---------------------+
5. | 15 |
6. +---------------------+
7. 1 row in set (0.09 sec)
8.
9. mysql> select nextval('MovieSeq');
10. +---------------------+
11. | nextval('MovieSeq') |
12. +---------------------+
13. | 20 |
14. +---------------------+
15. 1 row in set (0.01 sec)
16.
17. mysql> select nextval('MovieSeq');
18. +---------------------+
19. | nextval('MovieSeq') |
20. +---------------------+
21. | 25 |
22. +---------------------+
23. 1 row in set (0.00 sec)
setval
Java代码
1. DROP FUNCTION IF EXISTS setval;
2. DELIMITER $
3. CREATE FUNCTION setval (seq_name VARCHAR(50), value INTEGER)
4. RETURNS INTEGER
5. CONTAINS SQL
6. BEGIN
7. UPDATE sequence
8. SET current_value = value
9. WHERE name = seq_name;
10. RETURN currval(seq_name);
11. END$
12. DELIMITER ;
Java代码
1. mysql> select setval('MovieSeq',150);
2. +------------------------+
3. | setval('MovieSeq',150) |
4. +------------------------+
5. | 150 |
6. +------------------------+
7. 1 row in set (0.06 sec)
8.
9. mysql> select curval('MovieSeq');
10. +---------------------+
11. | currval('MovieSeq') |
12. +---------------------+
13. | 150 |
14. +---------------------+
15. 1 row in set (0.00 sec)
16.
17. mysql> select nextval('MovieSeq');
18. +---------------------+
19. | nextval('MovieSeq') |
20. +---------------------+
21. | 155 |
22. +---------------------+
23. 1 row in set (0.00 sec)
作者“ERDP技术架构”
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