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

这将重置所有来自public的序列,不假设表或列名。在8.4版上测试

CREATE OR REPLACE FUNCTION "reset_sequence" (tablename text, columnname text, sequence_name text) 
    RETURNS "pg_catalog"."void" AS 
    
    $body$  
      DECLARE 
      BEGIN 
    
      EXECUTE 'SELECT setval( ''' || sequence_name  || ''', ' || '(SELECT MAX(' || columnname || 
          ') FROM ' || tablename || ')' || '+1)';
    
      END;  
    
    $body$  LANGUAGE 'plpgsql';
    
    
SELECT table_name || '_' || column_name || '_seq', 
    reset_sequence(table_name, column_name, table_name || '_' || column_name || '_seq') 
FROM information_schema.columns where column_default like 'nextval%';

其他回答

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();
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

重置所有序列,除了每个表的主键是“id”外,对名称没有任何假设:

CREATE OR REPLACE FUNCTION "reset_sequence" (tablename text, columnname text)
RETURNS "pg_catalog"."void" AS
$body$
DECLARE
BEGIN
    EXECUTE 'SELECT setval( pg_get_serial_sequence(''' || tablename || ''', ''' || columnname || '''),
    (SELECT COALESCE(MAX(id)+1,1) FROM ' || tablename || '), false)';
END;
$body$  LANGUAGE 'plpgsql';

select table_name || '_' || column_name || '_seq', reset_sequence(table_name, column_name) from information_schema.columns where column_default like 'nextval%';

选择setval…使JDBC变得无聊,所以这里有一种与java兼容的方法:

-- work around JDBC 'A result was returned when none was expected.'
-- fix broken nextval due to poorly written 20140320100000_CreateAdminUserRoleTables.sql
DO 'BEGIN PERFORM setval(pg_get_serial_sequence(''admin_user_role_groups'', ''id''), 1 + COALESCE(MAX(id), 0), FALSE) FROM admin_user_role_groups; END;';

这个问题发生在我使用实体框架创建数据库,然后用初始数据播种数据库时,这使得序列不匹配。

我通过创建一个脚本来解决这个问题,在播种数据库后运行:

DO
$do$
DECLARE tablename text;
BEGIN
    -- change the where statments to include or exclude whatever tables you need
    FOR tablename IN SELECT table_name FROM information_schema.tables WHERE table_schema='public' AND table_type='BASE TABLE' AND table_name != '__EFMigrationsHistory'
        LOOP
            EXECUTE format('SELECT setval(pg_get_serial_sequence(''"%s"'', ''Id''), (SELECT MAX("Id") + 1 from "%s"))', tablename, tablename);
    END LOOP;
END
$do$