Sql Postgres-如何创建字母数字序列,如AA0000等
我想创建一个字母数字序列,如下所示:Sql Postgres-如何创建字母数字序列,如AA0000等,sql,perl,postgresql-9.4,Sql,Perl,Postgresql 9.4,我想创建一个字母数字序列,如下所示: AAAA0000 AAAA0001 AAAA0002 AAAA0003 . . . AAAA9999 AAAB0000 AAAB0001 等等 我创建了此存储过程来执行此操作,但速度太慢: CREATE OR REPLACE FUNCTION public.fn_batch_seq() RETURNS text LANGUAGE plpgsql AS $body$ DECLARE v_sequence TEXT := ''; v_next_
AAAA0000
AAAA0001
AAAA0002
AAAA0003
.
.
.
AAAA9999
AAAB0000
AAAB0001
等等
我创建了此存储过程来执行此操作,但速度太慢:
CREATE OR REPLACE FUNCTION public.fn_batch_seq()
RETURNS text
LANGUAGE plpgsql
AS
$body$
DECLARE
v_sequence TEXT := '';
v_next_sequence TEXT := '';
v_existing_id BIGINT := 0;
BEGIN
/*
* VARCHAR BATCH SEQUENCE FOR SIMCARDS
*/
SELECT "sequence" FROM batch_sequence WHERE id = 1 INTO v_sequence;
IF v_sequence = '' THEN
RAISE NOTICE 'Error - No existe ningun registro en batch_sequence almacenado';
RETURN -500;
END IF;
SELECT perl_increment(v_sequence) INTO v_next_sequence;
IF v_next_sequence = '' THEN
RAISE NOTICE 'Error - La siguiente secuencia generada devolvio null o vacio';
RETURN -500;
END IF;
UPDATE batch_sequence SET "sequence" = v_next_sequence WHERE id = 1;
RETURN v_next_sequence;
EXCEPTION WHEN OTHERS THEN
/*
* Other errors
*/
RAISE NOTICE 'Error General - Posibles causas: No existe la tabla batch_sequence o no existe ningun registro en la misma';
RETURN -500;
END;
$body$
VOLATILE
COST 100;
此过程使用表格存储序列:
CREATE TABLE batch_sequence
(
id serial NOT NULL,
sequence text DEFAULT 'AAAA0000'::text NOT NULL
);
-- Column id is associated with sequence public.batch_sequence_id_seq
ALTER TABLE batch_sequence
ADD CONSTRAINT batch_sequence_pk
PRIMARY KEY (id);
对于增量序列,我使用perl过程:
CREATE OR REPLACE FUNCTION public.perl_increment(text)
RETURNS text
LANGUAGE plperl
AS
$body$
my ($x) = @_;
if (not defined $x) {
return undef;
}
++$x;
$body$
VOLATILE
COST 100;
它处理大量数据的速度非常慢,因为它必须在插入每一行之前执行。有没有其他方法可以使用Perl或不使用Perl
请帮忙
它处理大量数据的速度非常慢,因为它必须在插入每一行之前执行。有没有其他方法可以使用Perl或不使用Perl
第一个选项:
创建一个序列并对其进行解码:
CREATE SEQUENCE my_serial START 11110000;
翻译成字母左部分:
select nextval(''my_serial'') INTO v_nextSeq ;
select translate(
left( trim(to_char(v_nextSeq,'9999')), 4),
'12345','ABCDE')
||
right( trim(to_char(v_nextSeq,'9999')), 4);
第二选项:
您可以保留所有序列号,然后使用它:
**将used
字段添加到架构中,记住在序列**上创建索引:
CREATE TABLE batch_sequence
(
id serial NOT NULL,
sequence text DEFAULT 'AAA'::text NOT NULL,
used boolean default false
);
填充整个表格,此处仅简化为两位数字:
with s as (
SELECT A.a || B.b as sequence
FROM unnest(string_to_array('A B C',' ')) A
CROSS JOIN unnest(string_to_array('0 1 2 3 4 5 6 7 8 9',' ')) B
)
insert into batch_sequence ( sequence )
select s.sequence
from s;
select * from batch_sequence
| id | sequence | used |
|----|----------|-------|
| 28 | A0 | false |
| 29 | A1 | false |
| 30 | A2 | false |
| 31 | A3 | false |
| 32 | A4 | false |
| 33 | A5 | false |
| 34 | A6 | false |
| 35 | A7 | false |
| 36 | A8 | false |
| 37 | A9 | false |
| 38 | B0 | false |
| 39 | B1 | false |
| 40 | B2 | false |
| 41 | B3 | false |
| 42 | B4 | false |
| 43 | B5 | false |
| 44 | B6 | false |
| 45 | B7 | false |
| 46 | B8 | false |
| 47 | B9 | false |
| 48 | C0 | false |
| 49 | C1 | false |
| 50 | C2 | false |
| 51 | C3 | false |
| 52 | C4 | false |
| 53 | C5 | false |
| 54 | C6 | false |
| 55 | C7 | false |
| 56 | C8 | false |
| 57 | C9 | false |
:
with s as (
SELECT A.a || B.b as sequence
FROM unnest(string_to_array('A B C',' ')) A
CROSS JOIN unnest(string_to_array('0 1 2 3 4 5 6 7 8 9',' ')) B
)
insert into batch_sequence ( sequence )
select s.sequence
from s;
select * from batch_sequence
| id | sequence | used |
|----|----------|-------|
| 28 | A0 | false |
| 29 | A1 | false |
| 30 | A2 | false |
| 31 | A3 | false |
| 32 | A4 | false |
| 33 | A5 | false |
| 34 | A6 | false |
| 35 | A7 | false |
| 36 | A8 | false |
| 37 | A9 | false |
| 38 | B0 | false |
| 39 | B1 | false |
| 40 | B2 | false |
| 41 | B3 | false |
| 42 | B4 | false |
| 43 | B5 | false |
| 44 | B6 | false |
| 45 | B7 | false |
| 46 | B8 | false |
| 47 | B9 | false |
| 48 | C0 | false |
| 49 | C1 | false |
| 50 | C2 | false |
| 51 | C3 | false |
| 52 | C4 | false |
| 53 | C5 | false |
| 54 | C6 | false |
| 55 | C7 | false |
| 56 | C8 | false |
| 57 | C9 | false |
:
with s as (
SELECT A.a || B.b as sequence
FROM unnest(string_to_array('A B C',' ')) A
CROSS JOIN unnest(string_to_array('0 1 2 3 4 5 6 7 8 9',' ')) B
)
insert into batch_sequence ( sequence )
select s.sequence
from s;
select * from batch_sequence
| id | sequence | used |
|----|----------|-------|
| 28 | A0 | false |
| 29 | A1 | false |
| 30 | A2 | false |
| 31 | A3 | false |
| 32 | A4 | false |
| 33 | A5 | false |
| 34 | A6 | false |
| 35 | A7 | false |
| 36 | A8 | false |
| 37 | A9 | false |
| 38 | B0 | false |
| 39 | B1 | false |
| 40 | B2 | false |
| 41 | B3 | false |
| 42 | B4 | false |
| 43 | B5 | false |
| 44 | B6 | false |
| 45 | B7 | false |
| 46 | B8 | false |
| 47 | B9 | false |
| 48 | C0 | false |
| 49 | C1 | false |
| 50 | C2 | false |
| 51 | C3 | false |
| 52 | C4 | false |
| 53 | C5 | false |
| 54 | C6 | false |
| 55 | C7 | false |
| 56 | C8 | false |
| 57 | C9 | false |
创建一个函数来获取新的序列号,并将其设置为
used
,只需使用常规序列即可。创建一个函数,该函数获取其底层序列nextval
,然后将整数值转换为字母数字值。您所说的转换是什么意思?我该怎么做你有原始序列号121431。当原始数字大于或等于1000时,保持将该数字除以1000并增加左半部分(“AAAA”)。在结束时,使用零左填充将左部分(“ABCD”)与余数连接起来。