-- Login to psql and run the following

-- What is the result?
SELECT MAX(id) FROM your_table;

-- Then run...
-- This should be higher than the last result.
SELECT nextval('your_table_id_seq');

-- If it's not higher... run this set the sequence last to your highest id. 
-- (wise to run a quick pg_dump first...)

BEGIN;
-- protect against concurrent inserts while you update the counter
LOCK TABLE your_table IN EXCLUSIVE MODE;
-- Update the sequence
SELECT setval('your_table_id_seq', COALESCE((SELECT MAX(id)+1 FROM your_table), 1), false);
COMMIT;

来源- Ruby论坛

select 'SELECT SETVAL(' || seq [ 1] || ', COALESCE(MAX('||column_name||')+1, 1) ) FROM '||table_name||';'
from (
       SELECT table_name, column_name, column_default, regexp_match(column_default, '''.*''') as seq
       from information_schema.columns
       where column_default ilike 'nextval%'
     ) as sequense_query

我找不到Rails的明确答案。

从rails控制台

ActiveRecord::Base.connection.execute("SELECT setval(pg_get_serial_sequence('table_name', 'id'), MAX(id)) FROM table_name;")

例如将table_name替换为users。

更新模式中用作ID的所有序列的方法:

DO $$ DECLARE
  r RECORD;
BEGIN
FOR r IN (SELECT tablename, pg_get_serial_sequence(tablename, 'id') as sequencename
          FROM pg_catalog.pg_tables
          WHERE schemaname='YOUR_SCHEMA'
          AND tablename IN (SELECT table_name 
                            FROM information_schema.columns 
                            WHERE table_name=tablename and column_name='id')
          order by tablename)
LOOP
EXECUTE
        'SELECT setval(''' || r.sequencename || ''', COALESCE(MAX(id), 1), MAX(id) IS NOT null)
         FROM ' || r.tablename || ';';
END LOOP;
END $$;

ALTER SEQUENCE sequence_name RESTART WITH (SELECT max(id) FROM table_name); 是行不通的。

复制自@tardate答案:

SELECT setval(pg_get_serial_sequence('table_name', 'id'), MAX(id)) FROM table_name;

试着重建索引。

更新:正如评论中指出的，这是对最初问题的回答。