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我正在创建一个项目记录编号生成器。目标是有一个表格来容纳各种不同类型的所有记录号/序列器。例如，对于“零件”，您可能需要像“110-00001-00”这样的数字。seqItem 表将保存此数字生成器的定义（SeqName、preFix、postFix、填充）。

InventorySys=# SELECT * FROM information_schema.sequences;
 sequence_catalog | sequence_schema | sequence_name | data_type | numeric_precision | numeric_precision_radix | numeric_scale | start_value | minimum_value | maximum_value | increment | cycle_option
------------------+-----------------+---------------+-----------+-------------------+-------------------------+---------------+-------------+---------------+---------------+-----------+--------------
(0 rows)


InventorySys=# \d "SeqItem"
               Table "public.SeqItem"
 Column  |  Type   | Collation | Nullable | Default
---------+---------+-----------+----------+---------
 SeqName | text    |           | not null |
 prefix  | text    |           |          |
 postfix | text    |           |          |
 padding | integer |           | not null | 5
Indexes:
    "SeqItem_pkey" PRIMARY KEY, btree ("SeqName")
    "SeqName" UNIQUE CONSTRAINT, btree ("SeqName")
Triggers:
    dropsqeitem AFTER DELETE ON "SeqItem" FOR EACH ROW EXECUTE FUNCTION "RemoveSeq"()
    inssqeitem AFTER INSERT ON "SeqItem" FOR EACH ROW EXECUTE FUNCTION "CreateSeq"()


InventorySys=#

当向该表添加新记录时，我想使用“SeqName”创建一个新序列。因此，我创建了以下触发器/函数：

CREATE OR REPLACE FUNCTION public."CreateSeq"() RETURNS TRIGGER  as $CreateSeq$
BEGIN
EXECUTE  format('CREATE SEQUENCE %I INCREMENT BY 1 MINVALUE 1 NO MAXVALUE START WITH 1 NO CYCLE',  NEW."SeqName");
RETURN NEW;
END
$CreateSeq$ LANGUAGE plpgsql;

CREATE  TRIGGER insSqeItem AFTER INSERT ON "SeqItem"
    FOR EACH ROW EXECUTE FUNCTION "CreateSeq"();

这很完美，并且每创建一条新记录，我都会创建一个新的音序器。如果行被删除，我还创建了另一个函数/触发器来删除定序器。

CREATE OR REPLACE FUNCTION public."RemoveSeq"() RETURNS TRIGGER  as $RemoveSeq$
BEGIN
EXECUTE  format('DROP SEQUENCE IF EXISTS  %I',  OLD."SeqName");
RETURN NEW;
END
$RemoveSeq$ LANGUAGE plpgsql;

CREATE  TRIGGER dropSqeItem AFTER DELETE ON "SeqItem"
    FOR EACH ROW EXECUTE FUNCTION "RemoveSeq"();

到目前为止，一切都很好！所以，让我们添加一条新记录，看看是否添加了 Sequencer：

InventorySys=# INSERT into "SeqItem" ("SeqName", prefix, padding) Values ('testItem1', '115-',6);
INSERT 0 1
InventorySys=# SELECT * FROM "SeqItem";
  SeqName  | prefix | postfix | padding
-----------+--------+---------+---------
 testItem1 | 115-   |         |       6
(1 row)


InventorySys=# SELECT * FROM information_schema.sequences;
 sequence_catalog | sequence_schema | sequence_name | data_type | numeric_precision | numeric_precision_radix | numeric_scale | start_value | minimum_value |    maximum_value    | increment | cycle_option
------------------+-----------------+---------------+-----------+-------------------+-------------------------+---------------+-------------+---------------+---------------------+-----------+--------------
 InventorySys     | public          | testItem1     | bigint    |                64 |                       2 |             0 | 1           | 1             | 9223372036854775807 | 1         | NO
(1 row)


InventorySys=#

但是，当我尝试使用触发器中新创建的音序器时，我收到以下错误，即找不到音序器。

InventorySys=# select CONCAT("prefix", LPAD((select nextval("SeqItem"."SeqName"))::text, "padding", '0') , "postfix") from "SeqItem" where "SeqName" = 'testItem1' ;
ERROR:  relation "testitem1" does not exist
InventorySys=#

错误：关系“testitem1”不存在

如果我创建一个没有触发器的新序列器，它工作正常：

InventorySys=# CREATE SEQUENCE test1;
CREATE SEQUENCE
InventorySys=# SELECT NEXTVAL ('test1');
 nextval
---------
       1
(1 row)


InventorySys=#

如果我将该定序器添加到我的查询中，它可以正常工作：

InventorySys=# select CONCAT("prefix", LPAD((select nextval('test1'))::text, "padding", '0') , "postfix") from "SeqItem" where "SeqName" = 'testItem1' ;
   concat
------------
 115-000002
(1 row)


InventorySys=#

两个音序器对我来说都很好，但是由触发器创建的那个我无法开始工作......

InventorySys=#  SELECT * FROM information_schema.sequences;
 sequence_catalog | sequence_schema | sequence_name | data_type | numeric_precision | numeric_precision_radix | numeric_scale | start_value | minimum_value |    maximum_value    | increment | cycle_option
------------------+-----------------+---------------+-----------+-------------------+-------------------------+---------------+-------------+---------------+---------------------+-----------+--------------
 InventorySys     | public          | testItem1     | bigint    |                64 |                       2 |             0 | 1           | 1             | 9223372036854775807 | 1         | NO
 InventorySys     | public          | test1         | bigint    |                64 |                       2 |             0 | 1           | 1             | 9223372036854775807 | 1         | NO
(2 rows)


InventorySys=#

任何帮助将不胜感激！

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1 回答 1

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好的，我想我找到了我的问题。看来定序器名称需要全部小写？或者，我应该说，如果我使用所有小写字母，它就可以正常工作......

InventorySys=# INSERT into "SeqItem" ("SeqName", prefix, padding) Values ('testitem3', '110-',4);
INSERT 0 1

InventorySys=# select CONCAT("prefix", LPAD((select nextval("SeqItem"."SeqName"))::text, "padding", '0') , "postfix") from "SeqItem" where "SeqName" = 'testitem3' ;
  concat
----------
 110-0001
(1 row)


InventorySys=# select CONCAT("prefix", LPAD((select nextval("SeqItem"."SeqName"))::text, "padding", '0') , "postfix") from "SeqItem" where "SeqName" = 'testitem3' ;
  concat
----------
 110-0002
(1 row)


InventorySys=#

我不确定为什么它不接受大小写字符...

于 2020-10-04T19:38:15.663 回答