分享C#原生ID（流水号）生成功能实现

 　　/// <summary>
    /// 
    /// </summary>
    public static class DataBaseGenerator
    {
        /// <summary>
        /// 
        /// </summary>
        private static Int64 seed = Int64.Parse(DateTime.UtcNow.Subtract(new DateTime(1970, 1, 1)).TotalMilliseconds.ToString("0"));

        /// <summary>
        /// 
        /// </summary>
        /// <returns></returns>
        public static Int64 GetPrimaryKey()
        {
            return Interlocked.Increment(ref seed);
        }
    }

CREATE TABLE [dbo].[NumSeq] (
    [Cate] [varchar] (2)  NOT NULL ,
    [DateNo] [varchar] (4)  NOT NULL ,
    [Seq] [int] NULL ,
    [CrTime] [datetime] NOT NULL 
)

CREATE  PROC dpPMT_SGetMaintainSeq
@MaintainCate VARCHAR(2)

AS
--***********************累加编号*************************************************
DECLARE @MaintainNo VARCHAR(12) 
IF NOT EXISTS(SELECT 
            *
        FROM
            NumSeq
        WHERE
            Cate=@MaintainCate AND DATEDIFF(DAY,CrTime,GETDATE())=0)
    BEGIN
        INSERT INTO 
            NumSeq(Cate,DateNo,Seq)
        values(@MaintainCate,RIGHT(CONVERT(VARCHAR(4),YEAR(GETDATE())),2)+
                REPLICATE('0',2-LEN(MONTH(GETDATE())))+CONVERT(VARCHAR(2),MONTH(GETDATE())),0)

    END
ELSE
    BEGIN
        UPDATE
            NumSeq
        SET 
            Seq=Seq+1
        WHERE
            Cate=@MaintainCate AND DateNo=RIGHT(CONVERT(VARCHAR(4),YEAR(GETDATE())),2)+
                       REPLICATE('0',2-LEN(MONTH(GETDATE())))+CONVERT(VARCHAR(2),MONTH(GETDATE()))
    END

--************************组合编号***************************************************************
SELECT 
    @MaintainNo=Cate+DateNo+REPLICATE('0',6-LEN(Seq))+CONVERT(VARCHAR(6),Seq)
FROM
    NumSeq
WHERE
    Cate=@MaintainCate AND DateNo=RIGHT(CONVERT(VARCHAR(4),YEAR(GETDATE())),2)+
                      REPLICATE('0',2-LEN(MONTH(GETDATE())))+CONVERT(VARCHAR(2),MONTH(GETDATE()))

SELECT @MaintainNo