LINQ是Visual Studio 2008在重要内容之一,本节也主要是介绍如何利用LINQ来构建我们的数据层。
在本篇文章中用到了C#3.0的新特性,不了解的朋友可以到我的另一个系列《C#3.0 为我们带来什么》中查看,本篇中不再做过多介绍。
在数据库中建立City、Module、Province、User、UserGroup 5个表,如图1。
图1
数据库脚本
Code
if exists (select * from sysobjects where id = OBJECT_ID('[Citys]') and OBJECTPROPERTY(id, 'IsUserTable') = 1) DROP TABLE [Citys]
CREATE TABLE [Citys] ( [CityID] [int] IDENTITY (1, 1) NOT NULL , [Name] [nchar] (10) NULL , [ProvinceID] [int] NULL , [Code] [nchar] (20) NOT NULL )
ALTER TABLE [Citys] WITH NOCHECK ADD CONSTRAINT [PK_Citys] PRIMARY KEY NONCLUSTERED ( [CityID] )
SET IDENTITY_INSERT [Citys] ON
INSERT [Citys] ( [CityID] , [Name] , [ProvinceID] , [Code] ) VALUES ( 6 , '济南 ' , 1 , 'jinan ' )
INSERT [Citys] ( [CityID] , [Name] , [ProvinceID] , [Code] ) VALUES ( 7 , '青岛 ' , 1 , 'qingdao ' )
INSERT [Citys] ( [CityID] , [Name] , [ProvinceID] , [Code] ) VALUES ( 8 , '泰安 ' , 1 , 'taian ' )
SET IDENTITY_INSERT [Citys] OFF
if exists (select * from sysobjects where id = OBJECT_ID('[Modules]') and OBJECTPROPERTY(id, 'IsUserTable') = 1) DROP TABLE [Modules]
CREATE TABLE [Modules] ( [ModuleID] [int] IDENTITY (1, 1) NOT NULL , [Name] [nchar] (20) NULL , [Comments] [nchar] (50) NULL , [Code] [nchar] (20) NOT NULL )
ALTER TABLE [Modules] WITH NOCHECK ADD CONSTRAINT [PK_Modules] PRIMARY KEY NONCLUSTERED ( [ModuleID] )
SET IDENTITY_INSERT [Modules] ON
INSERT [Modules] ( [ModuleID] , [Name] , [Code] ) VALUES ( 1 , '用户管理 ' , 'ManageModule ' )
SET IDENTITY_INSERT [Modules] OFF
if exists (select * from sysobjects where id = OBJECT_ID('[Provinces]') and OBJECTPROPERTY(id, 'IsUserTable') = 1) DROP TABLE [Provinces]
CREATE TABLE [Provinces] ( [ProvinceID] [int] IDENTITY (1, 1) NOT NULL , [Name] [nchar] (10) NULL , [Code] [nchar] (20) NOT NULL )
ALTER TABLE [Provinces] WITH NOCHECK ADD CONSTRAINT [PK_Provinces] PRIMARY KEY NONCLUSTERED ( [ProvinceID] )
SET IDENTITY_INSERT [Provinces] ON
INSERT [Provinces] ( [ProvinceID] , [Name] , [Code] ) VALUES ( 1 , '山东 ' , 'shandong ' )
INSERT [Provinces] ( [ProvinceID] , [Name] , [Code] ) VALUES ( 2 , '北京 ' , 'beijing ' )
INSERT [Provinces] ( [ProvinceID] , [Name] , [Code] ) VALUES ( 3 , '上海 ' , 'shanghai ' )
SET IDENTITY_INSERT [Provinces] OFF
if exists (select * from sysobjects where id = OBJECT_ID('[UserGroups]') and OBJECTPROPERTY(id, 'IsUserTable') = 1) DROP TABLE [UserGroups]
CREATE TABLE [UserGroups] ( [GroupID] [int] IDENTITY (1, 1) NOT NULL , [Name] [nchar] (10) NULL , [Comments] [nchar] (100) NULL , [ModuleID] [int] NULL , [Code] [nchar] (20) NULL )
ALTER TABLE [UserGroups] WITH NOCHECK ADD CONSTRAINT [PK_UserGroups] PRIMARY KEY NONCLUSTERED ( [GroupID] )
SET IDENTITY_INSERT [UserGroups] ON
INSERT [UserGroups] ( [GroupID] , [Name] , [Comments] , [ModuleID] , [Code] ) VALUES ( 1 , '普通用户 ' , '普通用户 ' , 1 , 'pt ' )
INSERT [UserGroups] ( [GroupID] , [Name] , [Comments] , [ModuleID] , [Code] ) VALUES ( 2 , '管理员 ' , '管理员 ' , 1 , 'admin ' )
SET IDENTITY_INSERT [UserGroups] OFF
if exists (select * from sysobjects where id = OBJECT_ID('[Users]') and OBJECTPROPERTY(id, 'IsUserTable') = 1) DROP TABLE [Users]
CREATE TABLE [Users] ( [UserID] [int] IDENTITY (1, 1) NOT NULL , [UserName] [nchar] (50) NULL , [Password] [nchar] (50) NULL , [NickName] [nchar] (50) NULL , [GroupID] [int] NULL , [ProvinceID] [int] NULL , [CityID] [int] NULL , [EMail] [nchar] (50) NULL , [Question] [nchar] (20) NULL , [Answer] [nchar] (20) NULL , [Birthday] [nchar] (8) NULL , [RealName] [nchar] (10) NULL , [Sex] [bit] NULL )
ALTER TABLE [Users] WITH NOCHECK ADD CONSTRAINT [PK_Users] PRIMARY KEY NONCLUSTERED ( [UserID] )
SET IDENTITY_INSERT [Users] ON
INSERT [Users] ( [UserID] , [UserName] , [Password] , [GroupID] , [ProvinceID] , [CityID] ) VALUES ( 2 , 'admin ' , 'admin ' , 1 , 1 , 6 )
INSERT [Users] ( [UserID] , [UserName] , [Password] , [NickName] , [EMail] , [Question] , [Answer] , [Birthday] , [Sex] ) VALUES ( 3 , 'tianyamoon ' , '19820603 ' , '岳亮 ' , 'tiger133@163.com ' , '我就读的第一所学校的' , ' ' , '1982010' , 0 )
INSERT [Users] ( [UserID] , [UserName] , [Password] , [NickName] , [EMail] , [Question] , [Answer] , [Birthday] , [Sex] ) VALUES ( 4 , 'tianyamoon ' , '19820603 ' , ' ' , 'tiger133@163.com ' , '我就读的第一所学校的' , ' ' , '1982010' , 0 )
SET IDENTITY_INSERT [Users] OFF
if exists (select * from sysobjects where id = OBJECT_ID('[Citys]') and OBJECTPROPERTY(id, 'IsUserTable') = 1) DROP TABLE [Citys]
CREATE TABLE [Citys] ( [CityID] [int] IDENTITY (1, 1) NOT NULL , [Name] [nchar] (10) NULL , [ProvinceID] [int] NULL , [Code] [nchar] (20) NOT NULL )
ALTER TABLE [Citys] WITH NOCHECK ADD CONSTRAINT [PK_Citys] PRIMARY KEY NONCLUSTERED ( [CityID] )
SET IDENTITY_INSERT [Citys] ON
INSERT [Citys] ( [CityID] , [Name] , [ProvinceID] , [Code] ) VALUES ( 6 , '济南 ' , 1 , 'jinan ' )
INSERT [Citys] ( [CityID] , [Name] , [ProvinceID] , [Code] ) VALUES ( 7 , '青岛 ' , 1 , 'qingdao ' )
INSERT [Citys] ( [CityID] , [Name] , [ProvinceID] , [Code] ) VALUES ( 8 , '泰安 ' , 1 , 'taian ' )
SET IDENTITY_INSERT [Citys] OFF
if exists (select * from sysobjects where id = OBJECT_ID('[Modules]') and OBJECTPROPERTY(id, 'IsUserTable') = 1) DROP TABLE [Modules]
CREATE TABLE [Modules] ( [ModuleID] [int] IDENTITY (1, 1) NOT NULL , [Name] [nchar] (20) NULL , [Comments] [nchar] (50) NULL , [Code] [nchar] (20) NOT NULL )
ALTER TABLE [Modules] WITH NOCHECK ADD CONSTRAINT [PK_Modules] PRIMARY KEY NONCLUSTERED ( [ModuleID] )
SET IDENTITY_INSERT [Modules] ON
INSERT [Modules] ( [ModuleID] , [Name] , [Code] ) VALUES ( 1 , '用户管理 ' , 'ManageModule ' )
SET IDENTITY_INSERT [Modules] OFF
if exists (select * from sysobjects where id = OBJECT_ID('[Provinces]') and OBJECTPROPERTY(id, 'IsUserTable') = 1) DROP TABLE [Provinces]
CREATE TABLE [Provinces] ( [ProvinceID] [int] IDENTITY (1, 1) NOT NULL , [Name] [nchar] (10) NULL , [Code] [nchar] (20) NOT NULL )
ALTER TABLE [Provinces] WITH NOCHECK ADD CONSTRAINT [PK_Provinces] PRIMARY KEY NONCLUSTERED ( [ProvinceID] )
SET IDENTITY_INSERT [Provinces] ON
INSERT [Provinces] ( [ProvinceID] , [Name] , [Code] ) VALUES ( 1 , '山东 ' , 'shandong ' )
INSERT [Provinces] ( [ProvinceID] , [Name] , [Code] ) VALUES ( 2 , '北京 ' , 'beijing ' )
INSERT [Provinces] ( [ProvinceID] , [Name] , [Code] ) VALUES ( 3 , '上海 ' , 'shanghai ' )
SET IDENTITY_INSERT [Provinces] OFF
if exists (select * from sysobjects where id = OBJECT_ID('[UserGroups]') and OBJECTPROPERTY(id, 'IsUserTable') = 1) DROP TABLE [UserGroups]
CREATE TABLE [UserGroups] ( [GroupID] [int] IDENTITY (1, 1) NOT NULL , [Name] [nchar] (10) NULL , [Comments] [nchar] (100) NULL , [ModuleID] [int] NULL , [Code] [nchar] (20) NULL )
ALTER TABLE [UserGroups] WITH NOCHECK ADD CONSTRAINT [PK_UserGroups] PRIMARY KEY NONCLUSTERED ( [GroupID] )
SET IDENTITY_INSERT [UserGroups] ON
INSERT [UserGroups] ( [GroupID] , [Name] , [Comments] , [ModuleID] , [Code] ) VALUES ( 1 , '普通用户 ' , '普通用户 ' , 1 , 'pt ' )
INSERT [UserGroups] ( [GroupID] , [Name] , [Comments] , [ModuleID] , [Code] ) VALUES ( 2 , '管理员 ' , '管理员 ' , 1 , 'admin ' )
SET IDENTITY_INSERT [UserGroups] OFF
if exists (select * from sysobjects where id = OBJECT_ID('[Users]') and OBJECTPROPERTY(id, 'IsUserTable') = 1) DROP TABLE [Users]
CREATE TABLE [Users] ( [UserID] [int] IDENTITY (1, 1) NOT NULL , [UserName] [nchar] (50) NULL , [Password] [nchar] (50) NULL , [NickName] [nchar] (50) NULL , [GroupID] [int] NULL , [ProvinceID] [int] NULL , [CityID] [int] NULL , [EMail] [nchar] (50) NULL , [Question] [nchar] (20) NULL , [Answer] [nchar] (20) NULL , [Birthday] [nchar] (8) NULL , [RealName] [nchar] (10) NULL , [Sex] [bit] NULL )
ALTER TABLE [Users] WITH NOCHECK ADD CONSTRAINT [PK_Users] PRIMARY KEY NONCLUSTERED ( [UserID] )
SET IDENTITY_INSERT [Users] ON
INSERT [Users] ( [UserID] , [UserName] , [Password] , [GroupID] , [ProvinceID] , [CityID] ) VALUES ( 2 , 'admin ' , 'admin ' , 1 , 1 , 6 )
INSERT [Users] ( [UserID] , [UserName] , [Password] , [NickName] , [EMail] , [Question] , [Answer] , [Birthday] , [Sex] ) VALUES ( 3 , 'tianyamoon ' , '19820603 ' , '岳亮 ' , 'tiger133@163.com ' , '我就读的第一所学校的' , ' ' , '1982010' , 0 )
INSERT [Users] ( [UserID] , [UserName] , [Password] , [NickName] , [EMail] , [Question] , [Answer] , [Birthday] , [Sex] ) VALUES ( 4 , 'tianyamoon ' , '19820603 ' , ' ' , 'tiger133@163.com ' , '我就读的第一所学校的' , ' ' , '1982010' , 0 )
SET IDENTITY_INSERT [Users] OFF
打开上次创建的项目,按下Ctrl+W再按下Ctrl+L使用组合快捷键打开Server Explorer面板。
图2
点击黄色区域,添加数据链接,弹出如图3所示窗口.
图3
输入服务器名称及用户名、密码,并选择执行脚本的数据库,确定完成。
通过图4中展开的菜单,建立数据库连接。将上面的SQL脚本粘贴进打开的编辑器,按下F5执行向数据表插入演示数据。
图4
选中我们的项目使用快捷键Ctrl+Shift+A 选中Data,选中Linq to Sql Classes类型的文件,输入名称SecurityData.dbml按下确定。
图4
将图5中的5个表拖放到图6中的黄色位置。
图5
图6
保存文件,这样我们的数据库映射就建好了。
好,我们介绍下如何使用这个映射。创建一个WebForm,并在WebForm的OnLoad函数中输入下列代码来测试。