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 setval('sequencename', COALESCE((SELECT MAX(id)+1 FROM tablename), 1), false);

其他回答

如果您在加载自定义SQL数据进行初始化时看到此错误,另一种避免此错误的方法是:

而不是写:

INSERT INTO book (id, name, price) VALUES (1 , 'Alchemist' , 10),

从初始数据中删除id(主键)

INSERT INTO book (name, price) VALUES ('Alchemist' , 10),

这使Postgres序列保持同步!

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';

只需运行以下命令:

SELECT setval('my_table_seq', (SELECT max(id) FROM my_table));

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

所以我可以告诉你,在这个帖子里没有足够的意见或重新发明的轮子,所以我决定让事情变得有趣。

下面是一个程序:

关注(仅影响)与表相关的序列 适用于串行和生成的AS身份列 适用于good_column_names和“BAD_column_123”名称 如果表为空,则自动分配相应序列定义的起始值 允许只影响特定的序列(在schema.table.column表示法中) 有预览模式

CREATE OR REPLACE PROCEDURE pg_reset_all_table_sequences(
    IN commit_mode BOOLEAN DEFAULT FALSE
,   IN mask_in TEXT DEFAULT NULL
) AS
$$
DECLARE
    sql_reset TEXT;
    each_sec RECORD;
    new_val TEXT;
BEGIN

sql_reset :=
$sql$
SELECT setval(pg_get_serial_sequence('%1$s.%2$s', '%3$s'), coalesce(max("%3$s"), %4$s), false) FROM %1$s.%2$s;
$sql$
;

FOR each_sec IN (

    SELECT
        quote_ident(table_schema) as table_schema
    ,   quote_ident(table_name) as table_name
    ,   column_name
    ,   coalesce(identity_start::INT, seqstart) as min_val
    FROM information_schema.columns
    JOIN pg_sequence ON seqrelid = pg_get_serial_sequence(quote_ident(table_schema)||'.'||quote_ident(table_name) , column_name)::regclass
    WHERE
        (is_identity::boolean OR column_default LIKE 'nextval%') -- catches both SERIAL and IDENTITY sequences

    -- mask on column address (schema.table.column) if supplied
    AND coalesce( table_schema||'.'||table_name||'.'||column_name = mask_in, TRUE )
)
LOOP

IF commit_mode THEN
    EXECUTE format(sql_reset, each_sec.table_schema, each_sec.table_name, each_sec.column_name, each_sec.min_val) INTO new_val;
    RAISE INFO 'Resetting sequence for: %.% (%) to %'
        ,   each_sec.table_schema
        ,   each_sec.table_name
        ,   each_sec.column_name
        ,   new_val
    ;
ELSE
    RAISE INFO 'Sequence found for resetting: %.% (%)'
        ,   each_sec.table_schema
        ,   each_sec.table_name
        ,   each_sec.column_name
    ;
END IF
;

END LOOP;

END
$$
LANGUAGE plpgsql
;

预览:

调用pg_reset_all_table_sequences ();

提交:

调用pg_reset_all_table_sequences(真正的);

只指定你的目标表:

调用pg_reset_all_table_sequences(“schema.table.column”);