title: SEQUENCES summary: 了解 information_schema 表 SEQUENCES。

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;
  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(4)   | NO   |      | NULL    |       |
  8. | CACHE_VALUE     | bigint(21)   | YES  |      | NULL    |       |
  9. | CYCLE           | tinyint(4)   | 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)
  1. CREATE SEQUENCE test.seq;
  2. SELECT nextval(test.seq);
  3. SELECT * FROM sequences\G
  1. +-------------------+
  2. | nextval(test.seq) |
  3. +-------------------+
  4. |                 1 |
  5. +-------------------+
  6. 1 row in set (0.01 sec)
  7. *************************** 1. row ***************************
  8.   TABLE_CATALOG: def
  9. SEQUENCE_SCHEMA: test
  10.   SEQUENCE_NAME: seq
  11.           CACHE: 1
  12.     CACHE_VALUE: 1000
  13.           CYCLE: 0
  14.       INCREMENT: 1
  15.       MAX_VALUE: 9223372036854775806
  16.       MIN_VALUE: 1
  17.           START: 1
  18.         COMMENT: 
  19. 1 row in set (0.00 sec)