SEQUENCES

SEQUENCES 表提供了有关序列的信息。TiDB 中序列的功能是参照 MariaDB 中的类似功能来实现的。

1. USE INFORMATION_SCHEMA;
2. DESC SEQUENCES;

输出结果如下：

1. +-----------------+--------------+------+------+---------+-------+
2. | Field           | Type         | Null | Key  | Default | Extra |
3. +-----------------+--------------+------+------+---------+-------+
4. | TABLE_CATALOG   | varchar(512) | NO   |      | NULL    |       |
5. | SEQUENCE_SCHEMA | varchar(64)  | NO   |      | NULL    |       |
6. | SEQUENCE_NAME   | varchar(64)  | NO   |      | NULL    |       |
7. | CACHE           | tinyint(0)   | NO   |      | NULL    |       |
8. | CACHE_VALUE     | bigint(21)   | YES  |      | NULL    |       |
9. | CYCLE           | tinyint(0)   | NO   |      | NULL    |       |
10. | INCREMENT       | bigint(21)   | NO   |      | NULL    |       |
11. | MAX_VALUE       | bigint(21)   | YES  |      | NULL    |       |
12. | MIN_VALUE       | bigint(21)   | YES  |      | NULL    |       |
13. | START           | bigint(21)   | YES  |      | NULL    |       |
14. | COMMENT         | varchar(64)  | YES  |      | NULL    |       |
15. +-----------------+--------------+------+------+---------+-------+
16. 11 rows in set (0.00 sec)

创建一个名为 test.seq 的序列，并查询这个序列的下一个值：

1. CREATE SEQUENCE test.seq;
2. SELECT nextval(test.seq);

输出结果如下：

1. +-------------------+
2. | nextval(test.seq) |
3. +-------------------+
4. |                 1 |
5. +-------------------+
6. 1 row in set (0.01 sec)

查询数据库中的所有序列：

1. SELECT * FROM SEQUENCES\G

输出结果如下：

1. *************************** 1. row ***************************
2. TABLE_CATALOG: def
3. SEQUENCE_SCHEMA: test
4. SEQUENCE_NAME: seq
5. CACHE: 1
6. CACHE_VALUE: 1000
7. CYCLE: 0
8. INCREMENT: 1
9. MAX_VALUE: 9223372036854775806
10. MIN_VALUE: 1
11. START: 1
12. COMMENT:
13. 1 row in set (0.00 sec)