重新检查公共模式函数中的所有序列

CREATE OR REPLACE FUNCTION public.recheck_sequence (
)
RETURNS void AS
$body$
DECLARE
  _table_name VARCHAR;
  _column_name VARCHAR;  
  _sequence_name VARCHAR;
BEGIN
  FOR _table_name IN SELECT tablename FROM pg_catalog.pg_tables WHERE schemaname = 'public' LOOP
    FOR _column_name IN SELECT column_name FROM information_schema.columns WHERE table_name = _table_name LOOP
        SELECT pg_get_serial_sequence(_table_name, _column_name) INTO _sequence_name;
        IF _sequence_name IS NOT NULL THEN 
            EXECUTE 'SELECT setval('''||_sequence_name||''', COALESCE((SELECT MAX('||quote_ident(_column_name)||')+1 FROM '||quote_ident(_table_name)||'), 1), FALSE);';
        END IF;
    END LOOP;   
  END LOOP;
END;
$body$
LANGUAGE 'plpgsql'
VOLATILE
CALLED ON NULL INPUT
SECURITY INVOKER
COST 100;

更新模式中用作ID的所有序列的方法:

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

这个答案是从毛罗那里抄来的。

drop function IF EXISTS rebuilt_sequences() RESTRICT;
CREATE OR REPLACE FUNCTION  rebuilt_sequences() RETURNS integer as
$body$
  DECLARE sequencedefs RECORD; c integer ;
  BEGIN
    FOR sequencedefs IN Select
      DISTINCT(constraint_column_usage.table_name) as tablename,
      constraint_column_usage.column_name as columnname,
      replace(replace(columns.column_default,'''::regclass)',''),'nextval(''','') as sequencename
      from information_schema.constraint_column_usage, information_schema.columns
      where constraint_column_usage.table_schema ='public' AND 
      columns.table_schema = 'public' AND columns.table_name=constraint_column_usage.table_name
      AND constraint_column_usage.column_name = columns.column_name
      AND columns.column_default is not null 
      ORDER BY sequencename
   LOOP    
      EXECUTE 'select max('||sequencedefs.columnname||') from ' || sequencedefs.tablename INTO c;
      IF c is null THEN c = 0; END IF;
      IF c is not null THEN c = c+ 1; END IF;
      EXECUTE 'alter sequence ' || sequencedefs.sequencename ||' minvalue '||c ||' start ' || c ||' restart  with ' || c;
   END LOOP;

   RETURN 1; END;
$body$ LANGUAGE plpgsql;

select rebuilt_sequences();

Pg_get_serial_sequence可以用来避免任何关于序列名称的错误假设。这将在一个镜头中重置序列:

SELECT pg_catalog.setval(pg_get_serial_sequence('table_name', 'id'), (SELECT MAX(id) FROM table_name)+1);

或者更简洁地说:

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

然而，这个表单不能正确地处理空表，因为max(id)是空的，你也不能设置val 0，因为它超出了序列的范围。一种解决方法是使用ALTER SEQUENCE语法。

ALTER SEQUENCE table_name_id_seq RESTART WITH 1;
ALTER SEQUENCE table_name_id_seq RESTART; -- 8.4 or higher

但是ALTER SEQUENCE的用途有限，因为序列名和重启值不能是表达式。

似乎最好的通用解决方案是调用setval，将false作为第三个参数，允许我们指定“下一个要使用的值”:

SELECT setval(pg_get_serial_sequence('t1', 'id'), coalesce(max(id),0) + 1, false) FROM t1;

这符合我所有的条件:

避免硬编码实际的序列名 正确处理空表 使用现有数据处理表，并且不会留下 序列中的漏洞

最后，请注意，pg_get_serial_sequence仅在序列属于列时才有效。如果将递增列定义为串行类型，则会出现这种情况，但是如果手动添加序列，则需要确保ALTER sequence。“OWNED BY”也被执行。

例如，如果使用serial type来创建表，这应该都可以工作:

CREATE TABLE t1 (
  id serial,
  name varchar(20)
);

SELECT pg_get_serial_sequence('t1', 'id'); -- returns 't1_id_seq'

-- reset the sequence, regardless whether table has rows or not:
SELECT setval(pg_get_serial_sequence('t1', 'id'), coalesce(max(id),0) + 1, false) FROM t1;

但如果手动添加序列:

CREATE TABLE t2 (
  id integer NOT NULL,
  name varchar(20)
);

CREATE SEQUENCE t2_custom_id_seq
    START WITH 1
    INCREMENT BY 1
    NO MINVALUE
    NO MAXVALUE
    CACHE 1;

ALTER TABLE t2 ALTER COLUMN id SET DEFAULT nextval('t2_custom_id_seq'::regclass);

ALTER SEQUENCE t2_custom_id_seq OWNED BY t2.id; -- required for pg_get_serial_sequence

SELECT pg_get_serial_sequence('t2', 'id'); -- returns 't2_custom_id_seq'

-- reset the sequence, regardless whether table has rows or not:
SELECT setval(pg_get_serial_sequence('t2', 'id'), coalesce(max(id),0) + 1, false) FROM t1;

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。

之前我还没有尝试过代码:在下面我张贴 Klaus和user457226解决方案的sql代码版本 它在我的电脑上运行(Postgres 8.3)，只做了一些小调整 克劳斯的版本和我的user457226版本。

克劳斯解决方案:

drop function IF EXISTS rebuilt_sequences() RESTRICT;
CREATE OR REPLACE FUNCTION  rebuilt_sequences() RETURNS integer as
$body$
  DECLARE sequencedefs RECORD; c integer ;
  BEGIN
    FOR sequencedefs IN Select
      constraint_column_usage.table_name as tablename,
      constraint_column_usage.table_name as tablename, 
      constraint_column_usage.column_name as columnname,
      replace(replace(columns.column_default,'''::regclass)',''),'nextval(''','') as sequencename
      from information_schema.constraint_column_usage, information_schema.columns
      where constraint_column_usage.table_schema ='public' AND 
      columns.table_schema = 'public' AND columns.table_name=constraint_column_usage.table_name
      AND constraint_column_usage.column_name = columns.column_name
      AND columns.column_default is not null
   LOOP    
      EXECUTE 'select max('||sequencedefs.columnname||') from ' || sequencedefs.tablename INTO c;
      IF c is null THEN c = 0; END IF;
      IF c is not null THEN c = c+ 1; END IF;
      EXECUTE 'alter sequence ' || sequencedefs.sequencename ||' restart  with ' || c;
   END LOOP;

   RETURN 1; END;
$body$ LANGUAGE plpgsql;

select rebuilt_sequences();

User457226解决方案:

--drop function IF EXISTS reset_sequence (text,text) RESTRICT;
CREATE OR REPLACE FUNCTION "reset_sequence" (tablename text,columnname text) RETURNS bigint --"pg_catalog"."void"
AS
$body$
  DECLARE seqname character varying;
          c integer;
  BEGIN
    select tablename || '_' || columnname || '_seq' into seqname;
    EXECUTE 'SELECT max("' || columnname || '") FROM "' || tablename || '"' into c;
    if c is null then c = 0; end if;
    c = c+1; --because of substitution of setval with "alter sequence"
    --EXECUTE 'SELECT setval( "' || seqname || '", ' || cast(c as character varying) || ', false)'; DOES NOT WORK!!!
    EXECUTE 'alter sequence ' || seqname ||' restart with ' || cast(c as character varying);
    RETURN nextval(seqname)-1;
  END;
$body$ LANGUAGE 'plpgsql';

select sequence_name, PG_CLASS.relname, PG_ATTRIBUTE.attname,
       reset_sequence(PG_CLASS.relname,PG_ATTRIBUTE.attname)
from PG_CLASS
join PG_ATTRIBUTE on PG_ATTRIBUTE.attrelid = PG_CLASS.oid
join information_schema.sequences
     on information_schema.sequences.sequence_name = PG_CLASS.relname || '_' || PG_ATTRIBUTE.attname || '_seq'
where sequence_schema='public';