我有一个问题,我不知道如何用 Code First 的 CTP5 和 EF4 来表达。
编辑:在底部添加了我想通过 CF 复制的旧模式
这是我的具体情况:
团队是一个抽象概念;它应该存在于特定的一组特定的球员,特定的部门,特定的赛季。
NFL 的一个具体例子:
- 1996(赛季)AFC Central(分区)休斯顿油人队(队)
- 1997(赛季)AFC Central(分区)Tennessee Oilers(队)
- 1999(赛季)AFC Central(分区)Tennessee Titans(队)
- 2002(赛季)亚足联南部(分区)田纳西泰坦队(队)
这些都是同一个团队。我希望能够做到以下几点:
// Titans team id = 17
var myTeam = myContext.Teams.Single(t => t.Id == 17)
// display players
foreach (var p in myTeam.Seasons[1999].Players)
{
// Do something with the p here
}
// Display current division
Response.Write(myTeam.Seasons[2002].Division.Name);
我不确定 myTeam.Seasons 的 ICollection 成员变量中的特定查询语法,但概念应该是相同的。
谁能阐明您如何通过 EF4 CF CTP5 中的 CF 来表达这个概念?您将如何通过 Code First 来表达这一点?
当前 SQL 表
CREATE TABLE dbo.Season
(
Id INT IDENTITY(1,1) NOT NULL,
LeagueId INT NOT NULL,
[Name] NVARCHAR(50) NOT NULL,
[Year] CHAR(4) NOT NULL,
PrevSeasonId INT NULL
) ON [PRIMARY];
// Primary key
ALTER TABLE dbo.Season WITH NOCHECK ADD
CONSTRAINT PK_Season PRIMARY KEY NONCLUSTERED (Id) ON [PRIMARY];
CREATE TABLE dbo.Division
(
Id INT IDENTITY(1,1) NOT NULL,
DefaultName NVARCHAR(50) NOT NULL
) ON [PRIMARY];
// Primary key
ALTER TABLE dbo.Division WITH NOCHECK ADD
CONSTRAINT PK_Division PRIMARY KEY NONCLUSTERED (Id) ON [PRIMARY];
// Key Relation Table
CREATE TABLE dbo.DivisionsInSeason
(
DivisionId INT NOT NULL,
SeasonId INT NOT NULL,
DefaultName NVARCHAR(50) NOT NULL,
Commissioner UNIQUEIDENTIFIER NOT NULL,
ParentDivId INT NULL
) ON [PRIMARY];
// Primary Key
ALTER TABLE dbo.DivisionsInSeason WITH NOCHECK ADD
CONSTRAINT PK_DivisionsInSeason PRIMARY KEY NONCLUSTERED (DivisionId, SeasonId) ON [PRIMARY] ;
// Foreign Keys
ALTER TABLE dbo.DivisionsInSeason WITH CHECK ADD
CONSTRAINT FK_DivisionsInSeason_Division FOREIGN KEY(DivisionId) REFERENCES dbo.Division(Id),
CONSTRAINT FK_DivisionsInSeason_Season FOREIGN KEY(SeasonId) REFERENCES dbo.Season(Id),
CONSTRAINT FK_DivisionsInSeason_User FOREIGN KEY(Commissioner) REFERENCES dbo.[User](Id);
CREATE TABLE dbo.Team
(
Id INT IDENTITY(1,1) NOT NULL,
DefaultName NVARCHAR(50) NOT NULL,
DefShortName NCHAR(3) NULL
) ON [PRIMARY];
// Primary key
ALTER TABLE dbo.Team WITH NOCHECK ADD
CONSTRAINT PK_Team PRIMARY KEY NONCLUSTERED (Id) ON [PRIMARY] ;
// Key relationship table
CREATE TABLE dbo.TeamsInDivision
(
TeamId INT NOT NULL,
DivisionId INT NOT NULL,
SeasonId INT NOT NULL,
GeneralManager UNIQUEIDENTIFIER NOT NULL,
Name NVARCHAR(50) NOT NULL,
ShortName NCHAR(3) NULL
) ON [PRIMARY];
// Check Constraints
ALTER TABLE dbo.TeamsInDivision ADD
CONSTRAINT PK_TeamsInDivision PRIMARY KEY NONCLUSTERED (TeamId, DivisionId, SeasonId) ON [PRIMARY];
// Foreign Keys
ALTER TABLE dbo.TeamsInDivision WITH CHECK ADD
CONSTRAINT FK_TeamsInDivision_Team FOREIGN KEY(TeamId) REFERENCES dbo.Team(Id),
CONSTRAINT FK_TeamsInDivision_Division FOREIGN KEY(DivisionId) REFERENCES dbo.Division(Id),
CONSTRAINT FK_TeamsInDivision_Season FOREIGN KEY(SeasonId) REFERENCES dbo.Season(Id),
CONSTRAINT FK_TeamsInDivision_User FOREIGN KEY(GeneralManager) REFERENCES dbo.[User](Id);