基于sqlserver实现一个流水号生成器

创建表

SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

SET ANSI_PADDING ON
GO

CREATE TABLE [dbo].[nsc_serial_number](
	[id] [bigint] IDENTITY(1,1) NOT NULL,
	[name] [varchar](255) NULL,
	[year] [int] NOT NULL,
	[month] [int] NOT NULL,
	[day] [int] NOT NULL,
	[number] [bigint] NOT NULL,
 CONSTRAINT [PK_nsc_serial_number] PRIMARY KEY CLUSTERED 
(
	[id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY],
 CONSTRAINT [IX_nsc_serial_number] UNIQUE NONCLUSTERED 
(
	[day] ASC,
	[month] ASC,
	[year] ASC,
	[name] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

GO

SET ANSI_PADDING OFF
GO

创建存储过程

CREATE PROCEDURE [dbo].[nsc_get_next_serial_number](@name varchar(255),@year int,@month int,@day int)
AS
BEGIN
	-- SET NOCOUNT ON added to prevent extra result sets from
	-- interfering with SELECT statements.
	--SET NOCOUNT ON;
	declare @oldnumber bigint,
			@newnumber bigint,
			@id bigint
p:
	select @oldnumber = number,@id=id from nsc_serial_number where name=@name and year=@year and month=@month and day=@day;
	if(@oldnumber is null) 
		begin
		begin try
			insert into nsc_serial_number (name,year,month,day,number) values (@name,@year,@month,@day,0);
			set @oldnumber=0;
		end try begin catch 
			goto p;
		end catch
	end
	set @newnumber=@oldnumber+1;
	update nsc_serial_number set number = @newnumber where id=@id and number=@oldnumber;
	if(@@rowcount=0)
	begin
		goto p;
	end
	return @newnumber;
END

原理

1. 乐观锁
2. 唯一性约束

使用说明

1. name可以认为是前缀，year是年，month是月，day是日，前4个字段构成一个唯一值，id为自增主键。
2. 调用存储过程，传入name、年月日，即可返回不重复的序号，再和name等做个拼接，即可获取可用的流水号。