SQL根据日期自动编号

Question

sql数据库select

Answer 1

DECLARE @prefix varchar(8)
SET @prefix = CONVERT(varchar(8),GetDate(),112)SELECT @prefix+
       RIGHT('0000'+Convert(varchar(4),
                            ISNULL(CONVERT(int,MAX(SUBSTRING(a,9,4))),
                                   0)+1
                           ),
             4)
  FROM AAA
 WHERE a LIKE @prefix+'%'

Answer 2

SELECT ISNULL(LEFT(T2.a,8)+RIGHT('000'+CAST(RIGHT(T2.a,4)+1 AS VARCHAR(10)),4),T1.a)a FROM
(SELECT CONVERT(VARCHAR(8),GETDATE(),112)+'0001' a)T1
LEFT JOIN AAA T2 ON LEFT(T1.a,8)=LEFT(T2.a,8)