Warning: file_get_contents(/data/phpspider/zhask/data//catemap/6/entity-framework/4.json): failed to open stream: No such file or directory in /data/phpspider/zhask/libs/function.php on line 167

Warning: Invalid argument supplied for foreach() in /data/phpspider/zhask/libs/tag.function.php on line 1116

Notice: Undefined index: in /data/phpspider/zhask/libs/function.php on line 180

Warning: array_chunk() expects parameter 1 to be array, null given in /data/phpspider/zhask/libs/function.php on line 181

Warning: file_get_contents(/data/phpspider/zhask/data//catemap/0/drupal/3.json): failed to open stream: No such file or directory in /data/phpspider/zhask/libs/function.php on line 167

Warning: Invalid argument supplied for foreach() in /data/phpspider/zhask/libs/tag.function.php on line 1116

Notice: Undefined index: in /data/phpspider/zhask/libs/function.php on line 180

Warning: array_chunk() expects parameter 1 to be array, null given in /data/phpspider/zhask/libs/function.php on line 181
Entity framework 与EF4的多对多关系和代码优先_Entity Framework_Entity Framework 4_Ef Code First - Fatal编程技术网

Entity framework 与EF4的多对多关系和代码优先

Entity framework 与EF4的多对多关系和代码优先,entity-framework,entity-framework-4,ef-code-first,Entity Framework,Entity Framework 4,Ef Code First,我有一个问题,我不知道如何先用CTP5的代码和EF4来表达 编辑:在底部添加了我希望通过CF复制的旧模式 以下是我的具体场景: 团队是一个抽象的概念;它应该存在于特定的球员群体中,在特定的分区中,在特定的赛季中 NFL提供了一个具体的例子: 1996赛季AFC中区休斯顿石油队 1997赛季AFC中区田纳西加油队 1999赛季AFC中区田纳西泰坦队 2002赛季AFC南区田纳西泰坦队 这些都是同一个队。我希望能够做到以下几点: // Titans team id = 17 var myTeam =

我有一个问题,我不知道如何先用CTP5的代码和EF4来表达

编辑:在底部添加了我希望通过CF复制的旧模式

以下是我的具体场景:

团队是一个抽象的概念;它应该存在于特定的球员群体中,在特定的分区中,在特定的赛季中

NFL提供了一个具体的例子:

1996赛季AFC中区休斯顿石油队 1997赛季AFC中区田纳西加油队 1999赛季AFC中区田纳西泰坦队 2002赛季AFC南区田纳西泰坦队 这些都是同一个队。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成员变量中的具体查询语法,但概念应该是相同的

有人能解释一下您如何通过EF4 CF CTP5中的CF来表达这个概念吗? 您将如何首先通过代码来表达这一点

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);

也许这会有用


也许这会有用