使用sql存储过程生成字母数字序列

Question

我需要使用主键自动生成员工参考号唯一序列。示例Refno：（A0001-Z9999）现在已经执行了最大计数（Z9999） 我要生成的下一个序列：

AA001-AA999,
AB001-AB999, 
AZ999-BA001
BC001-BZ999,
CA001-CZ999,
ZA001-ZZ999..LIKE THIS..IN sql server stored procedure..

...ZZ999 LIKE THIS

Answer 1

你可以这样做。

首先创建一个SEQUENCE来生成从1开始的整数序列号。

CREATE SEQUENCE dbo.MySeq AS INT
    START WITH 1
    INCREMENT BY 1;

然后创建一个存储过程，生成所需格式的序列代码。

CREATE PROCEDURE dbo.up_GetNextSequence
(
    @seq nchar(5) out
)
AS
DECLARE @i int = NEXT VALUE FOR dbo.MySeq;

IF @i > 685323
BEGIN
    RAISERROR(N'Sequence is out of range.', 16, 0);
END

IF @i < 10000
BEGIN
    SET @seq = N'A' + FORMAT(@i, 'D4');
END
ELSE
BEGIN
    DECLARE @j int;
    SET @j = @i - 9999;

    DECLARE @k int;
    SET @k = ((@j - 1) % 999) + 1;

    DECLARE @l int;
    SET @l = (@j - 1) / 999;

    DECLARE @m int;
    SET @m = (@l % 26) + 65;

    DECLARE @n int;
    SET @n = (@l / 26) + 65;

    SET @seq = NCHAR(@n) + NCHAR(@m) + FORMAT(@k, 'D3');
END;

然后测试存储过程。

DECLARE @seq nchar(5);
EXEC up_GetNextSequence @seq output;
SELECT @seq AS '@seq'

再打四次，我们到达“A0005”。

要测试第一个断点，请更改序列对象，使其返回9999.然后再次执行测试代码。

ALTER SEQUENCE dbo.MySeq
   RESTART WITH 9999;

等等......

ALTER SEQUENCE dbo.MySeq
    RESTART WITH 10998;

ALTER SEQUENCE dbo.MySeq
    RESTART WITH 35973;

ALTER SEQUENCE dbo.MySeq
    RESTART WITH 659349;

测试当它到达允许范围的末尾时会发生什么。

ALTER SEQUENCE dbo.MySeq
    RESTART WITH 685323;

再次执行存储过程并引发错误，表示序列超出范围。这是设计的。

Answer 2

此查询将为您提供所需的所有值：

--here we take all the english alphabet
;WITH chars AS (
SELECT CHAR(65) as chars, 65 as [level]
UNION ALL
SELECT CHAR([level]+1), [level]+1
FROM chars
WHERE [level]-65 < 25
), cte AS ( -- Here we take didits from 1 to 999
SELECT 1 as digits
UNION ALL
SELECT digits+1
FROM cte
WHERE digits < 999
), codes AS ( -- here we get all chars combinations "AA", "AB" etc
SELECT c1.chars+c2.chars as code
FROM chars c1
cross join chars c2
)

--And here come cortesian join to get all refnomes ou need
SELECT code + CASE WHEN LEN(digits) = 1 THEN CONCAT('00',cast(digits as nvarchar(1)))
            WHEN LEN(digits) = 2 THEN CONCAT('0',cast(digits as nvarchar(2)))
            ELSE cast(digits as nvarchar(3)) END  as Refno
FROM cte
CROSS JOIN codes
ORDER BY code
OPTION (maxrecursion 1000)

输出：

Refno
AA001
AA002
AA003
AA004
AA005
AA006
AA007
AA008
AA009
AA010
AA011
AA012
AA013
AA014
AA015
AA016
AA017
...
etc
ZZ999

~675324行

您可以将结果放入某个表和存储过程中，从该表中返回所需的值。