创建计算列的帮助（SQL Server 2008）

Question

你好。

需要帮助在这个表格上创建一个计算列：

USE [ScienceWorksSummary]

GO

/****** Object:  Table [dbo].[Authors_Articles]    Script Date: 04/07/2011 10:38:55 ******/
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

CREATE TABLE [dbo].[Authors_Articles](
    [IdAuthor] [int] NOT NULL,
    [IdArticle] [int] NOT NULL,
    [Part] [float] NULL,
 CONSTRAINT [PK_Authors_Articles] PRIMARY KEY CLUSTERED 
(
    [IdAuthor] ASC,
    [IdArticle] 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

计算列 (Part) 的目的是获取每个作者编写同一篇文章的工作部分。例如，如果idAuthor = 1，idArticle = 1和idAuthor = 2，idArticle = 1，则每个人的 Part 值必须为0.5。

感谢您的帮助！

- DeadDream

Answer 1

CREATE TABLE [dbo].[Authors_Articles](
    [IdAuthor] [int] NOT NULL,
    [IdArticle] [int] NOT NULL,
 CONSTRAINT [PK_Authors_Articles] PRIMARY KEY CLUSTERED 
(
    [IdAuthor] ASC,
    [IdArticle] ASC
))
GO
create function dbo.calcPart(@IdArticle int) returns float as
begin
return (Select 1.0/count(*) from [Authors_Articles] where IdArticle = @IdArticle)
end
GO
alter table Authors_Articles add Part as dbo.calcPart(IdArticle)

- RichardTheKiwi

---

谢谢！ :) 将1.0/count()更改为ROUND((1.0/count()),2)，我得到了我需要的东西！ - DeadDream