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)