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SEQUENCES

SEQUENCES 表提供关于序列的信息。sequences feature 模仿了 MariaDB 中的类似功能。

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 行,耗时 0.00 秒

创建一个序列 test.seq 并查询序列的下一个值:

CREATE SEQUENCE test.seq;
SELECT NEXTVAL(test.seq);
SELECT * FROM sequences\G

输出结果如下:

+-------------------+
| NEXTVAL(test.seq) |
+-------------------+
|                 1 |
+-------------------+
1 行,耗时 0.01 秒

查看所有序列:

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 行,耗时 0.00 秒

See also