基于年度的主键？

Question

如何在SQL Server 2005/2008中使用以下格式创建主键: CurrentYear + auto-increment？

示例:当前年份为2010年,在新表中,ID应从1开始,因此:20101,20102,20103,20104,20105 ......等等.

Answer 1

该清洁的解决方案是创建一个复合主键由例如Year和Counter列.

Answer 2

这在技术上满足您的要求：

CREATE TABLE #test
        ( seeded_column INT IDENTITY(1,1) NOT NULL
        , year_column INT NOT NULL DEFAULT(YEAR(GETDATE()))
        , calculated_column AS CONVERT(BIGINT, CONVERT(CHAR(4), year_column, 120) + CONVERT(VARCHAR(MAX), seeded_column)) PERSISTED PRIMARY KEY
        , test VARCHAR(MAX) NOT NULL);

INSERT INTO #test (test)
SELECT 'Badda'
UNION ALL
SELECT 'Cadda'
UNION ALL
SELECT 'Dadda'
UNION ALL
SELECT 'Fadda'
UNION ALL
SELECT 'Gadda'
UNION ALL
SELECT 'Hadda'
UNION ALL
SELECT 'Jadda'
UNION ALL
SELECT 'Kadda'
UNION ALL
SELECT 'Ladda'
UNION ALL
SELECT 'Madda'
UNION ALL
SELECT 'Nadda'
UNION ALL
SELECT 'Padda';

SELECT *
FROM #test;

DROP TABLE #test;