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。

USE INFORMATION_SCHEMA; DESC SEQUENCES;

输出结果如下:

+-----------------+--------------+------+------+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-----------------+--------------+------+------+---------+-------+ | TABLE_CATALOG | varchar(512) | NO | | NULL | | | SEQUENCE_SCHEMA | varchar(64) | NO | | NULL | | | SEQUENCE_NAME | varchar(64) | NO | | NULL | | | CACHE | tinyint(0) | NO | | NULL | | | CACHE_VALUE | bigint(21) | YES | | NULL | | | CYCLE | tinyint(0) | NO | | NULL | | | INCREMENT | bigint(21) | NO | | NULL | | | MAX_VALUE | bigint(21) | YES | | NULL | | | MIN_VALUE | bigint(21) | YES | | NULL | | | START | bigint(21) | YES | | NULL | | | COMMENT | varchar(64) | YES | | NULL | | +-----------------+--------------+------+------+---------+-------+ 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:

CREATE SEQUENCE test.seq; SELECT NEXTVAL(test.seq);

输出结果如下:

+-------------------+ | NEXTVAL(test.seq) | +-------------------+ | 1 | +-------------------+ 1 row in set (0.01 sec)

查询数据库中的所有序列:

SELECT * FROM SEQUENCES\G

输出结果如下:

*************************** 1. row *************************** TABLE_CATALOG: def SEQUENCE_SCHEMA: test SEQUENCE_NAME: seq CACHE: 1 CACHE_VALUE: 1000 CYCLE: 0 INCREMENT: 1 MAX_VALUE: 9223372036854775806 MIN_VALUE: 1 START: 1 COMMENT: 1 row in set (0.00 sec)