postgresql修改自增序列

----删除前先解除 id 对该序列的依赖
ALTER TABLE tablename ALTER COLUMN id SET DEFAULT null;
DROP SEQUENCE IF EXISTS sequence_name;
---- id_max 即 id 目前的最大值，可写为1，可通过 “SELECT MAX(id) FROM tablename” 得到
CREATE SEQUENCE sequence_name START WITH id_max;
ALTER TABLE tablename ALTER COLUMN id SET DEFAULT nextval('sequence_name'::regclass);

示例
ALTER TABLE bookmarks ALTER COLUMN id SET DEFAULT null;
DROP SEQUENCE IF EXISTS bookmarks_id_seq
CREATE SEQUENCE bookmarks_id_seq START WITH 42920698;
ALTER TABLE bookmarks ALTER COLUMN id SET DEFAULT nextval('bookmarks_id_seq'::regclass);