SQL 生成可配置流水号

需求背景

每执行一次方法，根据公式返回最新的流水号。
第一次使用时需要先插入一条数据，BizSeqValue 为流水起始号：A2014030000，Formula 为公式：A[yyyy][mm][c4]，UseTime 为当前时间。

创建流水号表
CREATE TABLE [dbo].[SM_BizSeqNo](

    [BizSeqID] [int] IDENTITY(1,1) NOT NULL,
    [BizSeqValue][nvarchar](50) NULL,
    [BizSeqName] [nvarchar](50) NULL,[UseTime] [datetime] NULL,

    [Formula] [varchar](50) NULL)

创建PadLeft 函数
Create function [dbo].[PadLeft](@num varchar(16),@paddingChar char(1),@totalWidth int)

returns varchar(16) as

begin

if(len(@num)=0)

begin

    return ''

end

declare @curStr varchar(16)

select @curStr = isnull(replicate(@paddingChar,@totalWidth - len(isnull(@num ,0))), '') + @num

return @curStr

end

Create PROCEDURE [dbo].[Biz_GetSeqNo]

    @BizSeqType varchar(50)

AS

BEGIN

    declare

@BizSeqValue varchar(50),

@Prefix varchar(10),

@Year varchar(4),

@Yearindex int,

@Month varchar(2),

@Monthindex int,

@Day varchar(2),

@Dayindex int,

@DigitsIndex int,

@DigitsEndIndex int,

@Digits int,

@FlowNum varchar(50),

@Half1 varchar(50),

@Half2 varchar(50),

@Count int,

@Formula varchar(50)



set @Year='' set @Month='' set @Day=''

select @Formula=Formula,@BizSeqValue=BizSeqValue from SM_BizSeqNo where BizSeqType=@BizSeqType

select @Prefix=SUBSTRING(@Formula,0,charindex('[',@Formula))

select @DigitsIndex=charindex('[c',@Formula)

select @DigitsEndIndex=charindex(']',@Formula,@DigitsIndex+2)

select @Digits=SUBSTRING(@Formula,@DigitsIndex+2,@DigitsEndIndex-@DigitsIndex-2)

select @Yearindex=charindex('[yyyy]',@Formula)

if(@Yearindex>0)

begin

    select @year=YEAR(getdate())

end

else if(charindex('[yy]',@Formula)>0)

begin

    select @Yearindex=charindex('[yy]',@Formula)

    select @year=SUBSTRING(CAST(YEAR(getdate()) as varCHAR(4)),3,2)

end

select @monthindex=charindex('[mm]',@Formula)

if(@monthindex>0)

begin

    select @month=month(getdate())

end

select @dayindex=charindex('[dd]',@Formula)

if(@dayindex>0)

begin

    select @day=day(getdate())

end

select @Half1=@Prefix+@Year+dbo.PadLeft(@Month,'0',2)+dbo.PadLeft(@Day,'0',2)

--select @Half1,@Prefix,@Year

if(@Dayindex>0)

begin

    select @Half2=SUBSTRING(@Formula,@Dayindex+4,999)

    select @Count=COUNT(1) from SM_BizSeqNo where BizSeqType=@BizSeqType and DATEDIFF(DAY,UseTime,GETDATE())=0 

    select @DigitsIndex=@DigitsIndex-6

end

else if(@Monthindex>0)

begin

    select @Half2=SUBSTRING(@Formula,@Monthindex+4,999)

    select @Count=COUNT(1) from SM_BizSeqNo where BizSeqType=@BizSeqType and DATEDIFF(MONTH,UseTime,GETDATE())=0 

    select @DigitsIndex=@DigitsIndex-4

end

else if(@Yearindex>0)

begin

    select @Half2=SUBSTRING(@Formula,@Yearindex+2+LEN(@year),999)

    select @Count=COUNT(1) from SM_BizSeqNo where BizSeqType=@BizSeqType and DATEDIFF(YEAR,UseTime,GETDATE())=0 

    select @DigitsIndex=@DigitsIndex-2

end

else

begin

    select @Half2=SUBSTRING(@Formula,LEN(@Prefix)+1,999)

    select @Count=COUNT(1) from SM_BizSeqNo where BizSeqType=@BizSeqType

end

if(@Count>0) --当前流水号+1

begin

    select @FlowNum=cast(SUBSTRING(@BizSeqValue,@DigitsIndex,@Digits) as bigint)+1

    select @FlowNum=dbo.PadLeft(@FlowNum,'0',@Digits)

    update SM_BizSeqNo set BizSeqValue=@Half1+REPLACE(@Half2,'[c'+cast(@Digits as varchar(50))+']',@FlowNum),

    UseTime = GETDATE() where BizSeqType=@BizSeqType

end

else

begin

    select @FlowNum=dbo.PadLeft('1','0',@Digits)

    update SM_BizSeqNo set BizSeqValue=@Half1+REPLACE(@Half2,'[c'+cast(@Digits as varchar(50))+']',@FlowNum),

    UseTime = GETDATE() where BizSeqType=@BizSeqType

end

select BizSeqValue from SM_BizSeqNo where BizSeqType=@BizSeqType

END