每月初【流水号生成】从头开始

Question

流水号的格式为:年+月+流水号（如：201109001，201109002，201109003，......）
每个月的月初流水号将重头开始
一一年的十月为：201110001，201110002，......
一一年的十一月为：201111001,201111002，......
一一年的十二月为：201112001,201112002，201112003，......急，感谢了！

Answer 1

string 流水号 = string.Format("{0}{1}",DateTime.Now.ToString("yyyyMMdd"),序号);

Answer 2

            int id = 1;
            id = Convert.ToInt32(DateTime.Now.ToString("yyyyMM00")) + id;
            Console.Write(id);
            Console.Read();

Answer 3

增加一个数据表，放最少三个字段：年份、月份、流水号最大值。然后编写一个存储过程来生成流水号。读数据库的年份和月份来查流水号就OK了，没有该年月的流水则创建一条记录，否则修改并将流水号加1.设置长度，位数不足用0填充。Good Luck。

Answer 4

 //给你一个函数
public static string AutoReturnID(string TableName, string FiledName)
        {
            String sqlr = "select Max(" + FiledName + ")  from " + TableName + "";
            string ReturnID;
            using (OleDbConnection connection = new OleDbConnection(connectionString))
            {                OleDbCommand Command = new OleDbCommand(sqlr, connection);
                connection.Open();
                if (Command.ExecuteScalar() == null)
                {
                    ReturnID = DateTime.Now.Year.ToString("000") + DateTime.Now.Month.ToString("00") + DateTime.Now.Day.ToString("00") + "001";
                }
                else
                {
                   if (DateTime.Now.Day==1)
{  
ReturnID = DateTime.Now.Year.ToString("000") + DateTime.Now.Month.ToString("00") + DateTime.Now.Day.ToString("00") + "001";
else
{
                    string count = Convert.ToString(Command.ExecuteScalar());
                    count = count.Substring(count.Length - 3, 3);
                    ReturnID = DateTime.Now.Year.ToString("000") + DateTime.Now.Month.ToString("00") + DateTime.Now.Day.ToString("00") + (Convert.ToInt32(count) + 1).ToString("000");
}
                }
                Command.Dispose();
                connection.Close();
                return ReturnID;
            }
        }

Answer 5

public static string AutoReturnID(string TableName, string FiledName)
        {
            String sqlr = "select Max(" + FiledName + ")  from " + TableName + "";
            string ReturnID;
            using (OleDbConnection connection = new OleDbConnection(connectionString))
            {                OleDbCommand Command = new OleDbCommand(sqlr, connection);
                connection.Open();
                if (Command.ExecuteScalar() == null)
                {
                    ReturnID = DateTime.Now.Year.ToString("0000") + DateTime.Now.Month.ToString("00") + DateTime.Now.Day.ToString("00") + "001";
                }
                else
                {
                   if (DateTime.Now.Day==1)
{  
ReturnID = DateTime.Now.Year.ToString("0000") + DateTime.Now.Month.ToString("00") + DateTime.Now.Day.ToString("00") + "001";
}
else
{
                    string count = Convert.ToString(Command.ExecuteScalar());
                    count = count.Substring(count.Length - 3, 3);
                    ReturnID = DateTime.Now.Year.ToString("0000") + DateTime.Now.Month.ToString("00") + DateTime.Now.Day.ToString("00") + (Convert.ToInt32(count) + 1).ToString("000");
}
                }
                Command.Dispose();
                connection.Close();
                return ReturnID;
            }
        }

Answer 6

--在数据库做应该会好一些
--数据表 
DECLARE @Table TABLE(Number VARCHAR(20))
--测试数据
INSERT INTO @Table(Number)
SELECT '201110001' UNION ALL
SELECT '201110002' UNION ALL
SELECT '201110003' 
DECLARE @Number VARCHAR(20),@DateStr VARCHAR(6),@TotalCount INTSET @TotalCount = 1000
SELECT @DateStr = REPLACE(CONVERT(VARCHAR(7),GETDATE(),120),'-','')
SELECT @TotalCount = @TotalCount +ISNULL(COUNT(1),0) FROM @Table T WHERE LEFT(T.Number,6)=@DateStrSET @Number = @DateStr+RIGHT(LTRIM(@TotalCount+1),3)SELECT @Number/*
(3 行受影响)--------------------
201110004(1 行受影响)*/

Answer 7

http://topic.csdn.net/u/20110831/17/5f4bf99b-4245-4b99-9b46-3c3b387ea20a.html