我遇到了一个问题,我的主键序列与我的表行不同步。

也就是说,当我插入一个新行时,我得到一个重复的键错误,因为在串行数据类型中隐含的序列返回一个已经存在的数字。

这似乎是由于导入/恢复没有正确地维护序列造成的。


当前回答

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

其他回答

这里有很多很好的答案。在重新加载Django数据库后,我也有同样的需求。

但我需要:

All in one功能 可以一次修复一个或多个模式吗 可以修复所有或只是一个表的时间 还想要一个很好的方式来确切地看到什么改变了,或没有改变

这似乎与最初的要求非常相似。 多亏了Baldiry和Mauro让我找到了正确的方向。

drop function IF EXISTS reset_sequences(text[], text) RESTRICT;
CREATE OR REPLACE FUNCTION reset_sequences(
    in_schema_name_list text[] = '{"django", "dbaas", "metrics", "monitor", "runner", "db_counts"}',
    in_table_name text = '%') RETURNS text[] as
$body$
  DECLARE changed_seqs text[];
  DECLARE sequence_defs RECORD; c integer ;
  BEGIN
    FOR sequence_defs IN
        select
          DISTINCT(ccu.table_name) as table_name,
          ccu.column_name as column_name,
          replace(replace(c.column_default,'''::regclass)',''),'nextval(''','') as sequence_name
          from information_schema.constraint_column_usage ccu,
               information_schema.columns c
          where ccu.table_schema = ANY(in_schema_name_list)
            and ccu.table_schema = c.table_schema
            AND c.table_name = ccu.table_name
            and c.table_name like in_table_name
            AND ccu.column_name = c.column_name
            AND c.column_default is not null
          ORDER BY sequence_name
   LOOP
      EXECUTE 'select max(' || sequence_defs.column_name || ') from ' || sequence_defs.table_name INTO c;
      IF c is null THEN c = 1; else c = c + 1; END IF;
      EXECUTE 'alter sequence ' || sequence_defs.sequence_name || ' restart  with ' || c;
      changed_seqs = array_append(changed_seqs, 'alter sequence ' || sequence_defs.sequence_name || ' restart with ' || c);
   END LOOP;
   changed_seqs = array_append(changed_seqs, 'Done');

   RETURN changed_seqs;
END
$body$ LANGUAGE plpgsql;

然后执行并查看更改运行:

select *
from unnest(reset_sequences('{"django", "dbaas", "metrics", "monitor", "runner", "db_counts"}'));

返回

activity_id_seq                          restart at 22
api_connection_info_id_seq               restart at 4
api_user_id_seq                          restart at 1
application_contact_id_seq               restart at 20

重新启动所有序列到1使用:

-- Create Function
CREATE OR REPLACE FUNCTION "sy_restart_seq_to_1" (
    relname TEXT
)
RETURNS "pg_catalog"."void" AS
$BODY$

DECLARE

BEGIN
    EXECUTE 'ALTER SEQUENCE '||relname||' RESTART WITH 1;';
END;
$BODY$

LANGUAGE 'plpgsql';

-- Use Function
SELECT 
    relname
    ,sy_restart_seq_to_1(relname)
FROM pg_class
WHERE relkind = 'S';

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。

丑陋的黑客修复它使用一些贝壳魔法,不是一个伟大的解决方案,但可能会激励其他人有类似的问题:)

pg_dump -s <DATABASE> | grep 'CREATE TABLE' | awk '{print "SELECT setval(#" $3 "_id_seq#, (SELECT MAX(id) FROM " $3 "));"}' | sed "s/#/'/g" | psql <DATABASE> -f -

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;