.net+mssql制作抽奖程序思路及源码

抽奖程序:

思路整理无非就是点一个按钮然后一个图片旋转一会就出来个结果就行了可这个程序的要求不是这样的是需要从数据库中随机抽取用户根据数据库中指定的等级和人数一键全部抽出来结果就行了。同时需要存储到数据库。还需要一个导出的功能。

不能遗漏的是如果通过随机数根据id来抽取的话需要考虑id不连续的问题如果全部取出id也不现实。尽量少的去读写数据库。

数据库:

复制代码 代码如下:

CREATE TABLE [dbo].[users](
    [id] [int] IDENTITY(1,1) NOT NULL,
    [name] [nvarchar](50) NOT NULL,
    [phone] [nvarchar](50) NULL,
 CONSTRAINT [PK_table1] 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]
) ON [PRIMARY]

CREATE TABLE [dbo].[result](
 [id] [int] IDENTITY(1,1) NOT NULL,
 [usersid] [int] NOT NULL,
 [awardsid] [int] NOT NULL,
 CONSTRAINT [PK_result] 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]
) ON [PRIMARY]

CREATE TABLE [dbo].[awards](
 [id] [int] IDENTITY(1,1) NOT NULL,
 [Name] [nvarchar](50) NOT NULL,
 [Number] [int] NOT NULL,
 CONSTRAINT [PK_awards] 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]
) ON [PRIMARY]

CREATE VIEW [dbo].[view1]
AS
SELECT     dbo.result.id AS resultid, dbo.users.id, dbo.users.name, dbo.users.phone, dbo.awards.Name AS awardname
FROM         dbo.awards INNER JOIN
                      dbo.result ON dbo.awards.id = dbo.result.awardsid INNER JOIN
                      dbo.users ON dbo.result.usersid = dbo.users.id

CREATE PROCEDURE [dbo].[getranddata]
--这个地方的参数是后台调用传的参数两个变量之间需要“,”号分开
@count int, --剩余奖项大小
@awards int --奖项的id
AS BEGIN
--这个地方定义的参数是存储过程内部用到的
DECLARE @minid int --最大id
DECLARE @maxid int --最小id
DECLARE @randnum int --随机数临时变量
DECLARE @exist int --查询结果

SET @minid =
  (SELECT top 1 id
   FROM users
   ORDER BY id ASC) --查询最小id
SET @maxid =
  (SELECT top 1 id
   FROM users
   ORDER BY id DESC) --查询最大id
--set @count = 100
--set @awards = 1
--嵌套语句begin开始end结束
while @count>0 BEGIN
SELECT @randnum = ROUND(((@maxid - @minid -1) * RAND() + @minid), 0)
SET @exist =
  (SELECT count(*)
   FROM users
   WHERE id=@randnum) IF @exist = 1 BEGIN
INSERT INTO result(usersid,awardsid)
VALUES(@randnum,
       @awards)
SET @count = @count - 1 END END END

其中三张表一个视图一个存储过程。

后台代码:

复制代码 代码如下:

protected void Button1_Click(object sender, EventArgs e)
{
    SqlConnection sqlcon = new SqlConnection("server=.;database=test;uid=sa;pwd=123");
    sqlcon.Open();
    SqlDataAdapter sqlsda = new SqlDataAdapter("select * from awards", sqlcon);
    ds = new DataSet();
    sqlsda.Fill(ds);
    DataTable dt = ds.Tables[0].Copy();
    ds.Clear();
    int count = dt.Rows.Count;

    for (int i = 0; i < count; i++)
    {
        SqlCommand sqlcmd = new SqlCommand("getranddata", sqlcon);
        SqlParameter pcount = new SqlParameter("@count", Convert.ToInt32(dt.Rows[i]["Number"]));
        SqlParameter pawards = new SqlParameter("@awards", Convert.ToInt32(dt.Rows[i]["id"]));
        sqlcmd.Parameters.Add(pcount);
        sqlcmd.Parameters.Add(pawards);
        sqlcmd.CommandType = CommandType.StoredProcedure;
        sqlcmd.ExecuteNonQuery();

        sqlsda = new SqlDataAdapter("select top " + Convert.ToInt32(dt.Rows[i]["Number"]) + " * from view1 order by resultid desc", sqlcon);
        sqlsda.Fill(ds, "t" + i.ToString());

        switch (i)
        {
        case 0:
            GridView1.DataSource = ds.Tables["t" + i.ToString()].Copy().DefaultView;
            GridView1.DataBind();
            break;
        case 1:
            GridView2.DataSource = ds.Tables["t" + i.ToString()].Copy().DefaultView;
            GridView2.DataBind();
            break;
        case 2:
            GridView3.DataSource = ds.Tables["t" + i.ToString()].Copy().DefaultView;
            GridView3.DataBind();
            break;
        default:
            break;
        }
    }
    sqlcon.Close();
}

奖项设置:

抽奖结果:

=================================================================

知识点:

SQL - 生成指定范围内的随机数

复制代码 代码如下:

DECLARE @Result INT DECLARE @Upper INT DECLARE @Lower INT
SET @Lower = 1
SET @Upper = 10
SELECT @Result = ROUND(((@Upper - @Lower -1) * RAND() + @Lower), 0)
SELECT @Result

ROUND()函数:返回按指定位数进行四舍五入的数值。

RAND()函数:生成随机数。

SQL循环语句嵌套

复制代码 代码如下:

DECLARE @i int
SET @i=1 while @i<8 BEGIN IF @i<5 print space(4-@i)+REPLICATE('*',2*@i-1) ELSE print space(@i-4)+REPLICATE('*',15-2*@i)
SET @i=@i + 1 END



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