先说下原理：
根据前缀从表中取出符合该前缀的最大单号，或者最大批号/编码
然后在尾数上+1
单号规则为：【前缀】+【日期格式】+【流水】
日期可以没有，即：【前缀】+【流水】
-- =============================================
-- Author: 陈恩点
-- Create date: 2020-04-18
-- Description: 自动根据前缀生成新的编码
-- =============================================
ALTER PROCEDURE [dbo].[MyRapid_AutoBatchNo]
@BatchNo NVARCHAR(100) OUTPUT,
@TableName NVARCHAR(100),
@ColumnName NVARCHAR(100),
@Heard NVARCHAR(50) = 'SN',
@Format NVARCHAR(50) = 'yyyyMMdd',
@Length INT = 4
AS
BEGIN
DECLARE @Body NVARCHAR(100)
DECLARE @SqlScript NVARCHAR(MAX)
DECLARE @LastBatchNo NVARCHAR(100)
SET @Body = @Heard --+ CONVERT(NVARCHAR(50) ,GETDATE() ,112) --FORMAT(GETDATE(),@Format)
IF ISNULL(@Format ,'') != ''
BEGIN
SET @Body = @Heard + FORMAT(GETDATE(),@Format) --CONVERT(NVARCHAR(50) ,GETDATE() ,112)
END
----取出最大的符合条件的单号
--SELECT @LastBatchNo = ISNULL(MAX(LEFT(PurchaseOrder_Name,16)),'PORD202008120000')
----取符合条件的前面几位，字符串比对是从前向后依次比对
--FROM PSI_PurchaseOrder
--WHERE PurchaseOrder_Name LIKE 'PORD20200812____%'
----最后的%允许在合法批号后面添加后缀
--AND PATINDEX('%[^0-9]%' ,SUBSTRING(PurchaseOrder_Name,13,4)) = 0
----保证流水号是数字可以递增
SET @SqlScript = 'SELECT @LastBatchNo = ISNULL(MAX(LEFT(' + @ColumnName + ','+ CONVERT(NVARCHAR(50) ,LEN(@Body) + @Length) +')),'''+@Body + REPLICATE('0' ,@Length) +''')
FROM '+ @TableName +'
WHERE ' + @ColumnName + ' LIKE ''' + @Body + REPLICATE('_' ,@Length) + '%''
AND PATINDEX(''%[^0-9]%'' ,SUBSTRING('+ @ColumnName +',' + CONVERT(NVARCHAR(50),LEN(@Body) + 1) + ','+ CONVERT(NVARCHAR(50),@Length)+')) = 0' --这条件为了保证流水号是数字
PRINT @SqlScript
EXEC SP_EXECUTESQL @SqlScript ,N'@LastBatchNo NVARCHAR(100) OUT', @LastBatchNo OUT
DECLARE @BatchNo_Seed INT
DECLARE @BatchNo_Tail NVARCHAR(100)
SET @BatchNo_Tail = SUBSTRING(@LastBatchNo, LEN(@Body) + 1 ,@Length)
SET @BatchNo_Seed =CONVERT(INT,@BatchNo_Tail)+1
SET @BatchNo = @Body + REPLICATE ('0' ,@Length - LEN(@BatchNo_Seed) ) + CONVERT(NVARCHAR(100),@BatchNo_Seed)
END
GO