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：
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
原创文章，作者：bd101bd101，如若转载，请注明出处：https://blog.ytso.com/234729.html