一對多的外鍵太多

Question

此問題類似於：

為一對多關系編寫第一個多個外鍵代碼

和

實體框架代碼優先-來自同一表的兩個外鍵

但是還不足夠讓我尋求解決方案。

我有一個“團隊”模型，其中一個外鍵指向另一個名為“房間”的模型，一個團隊只能有一個房間。 房間模型有兩個團隊“ p2teams”和“ p3teams”列表。 實際上，在teams表中，它為房間創建了三個不同的id列：“ RoomID”，“ Room_RoomID”和“ Room_RoomID1”。

這導致我嘗試設置團隊的房間（例如exampleTeam.Room = exampleRoom），並且只影響RoomID列，而不影響其余部分。 此外，我只是真的不完全了解發生這種情況的結果。

以下是我的模型，數據庫圖以及團隊表中的一些示例數據。 謝謝您的幫助！

團隊模式：

public class Team
{
    public int TeamID { get; set; }

    public int HighschoolID { get; set; }
    public virtual Highschool Highschool { get; set; }
    public int ContestID { get; set; }
    public virtual Contest Contest { get; set; }

    [ForeignKey("Room")]
    public int? RoomID { get; set; }
    public virtual Room Room { get; set; }

    public string Warning { get; set; }

    public virtual ICollection<Student> Students { get; set; }
}

房間型號：

public class Room
{
    public int RoomID { get; set; }

    public virtual ICollection<RoomUsage> RoomUsages { get; set; }

    public string Name { get; set; }

    public int? AvailibleSeats { get; set; }
    public int? TotalSeats { get; set; }

    public virtual ICollection<Student> p1Students { get; set; }
    public virtual ICollection<Team> p2Teams { get; set; }
    public virtual ICollection<Team> p3Teams { get; set; }
}

相關數據庫圖圖像

球隊前幾行表格

再次感謝您的所有幫助。

Answer 1

實體框架行為正常。 如果設置“團隊室”屬性，則只會影響該表中的RoomID 。 其他列在“房間”表中更改。

您的房間表應該只有一個ICollection<Team> 。 如果您希望一個房間有多個團隊列表， TeamTypeID向“團隊”表中添加一個TeamTypeID 。 這樣，一個會議室可以擁有與TeamTypes一樣多的團隊列表。

因為您在“房間”表中有多個ICollection<Team> ，所以正在“團隊”表中生成其他列。

基於很多假設，我認為這兩個類應該看起來像

球隊：

public class Team
{

    public int TeamID { get; set; }

    public int? RoomID { get; set; }

    public string Warning { get; set; }

    public virtual Room Room { get; set; }

    public virtual ICollection<Student> Students { get; set; }

    public virtual ICollection<Contest> Contests { get; set; }
}

房間：

public class Room
{
    public int RoomID { get; set; }

    public string Name { get; set; }

    public int? AvailableSeats { get; set; }

    public int? TotalSeats { get; set; }

    public virtual ICollection<Student> Students { get; set; }

    public virtual ICollection<Team> Teams { get; set; }

    public virtual ICollection<Usage> Usages { get; set; }
}

我已經創建了一個腳本來創建數據庫表，並相信該腳本將基於更多的假設來實現您的目標：

• A student has
    One: Team, HighSchool, Room 
• A team has 
    One: Room
    Many: Contests 
• A room has 
    Many: Teams, Students, Usages 
• A contest has 
    Many: Teams 

如果仍然要先使用代碼，則可以使用Entity Framework從這些表中生成Code First類。

create table dbo.HighSchools
(
    HighSchoolID int primary key,
    Name varchar(50)

)

create table dbo.Rooms
(
    RoomID int primary key,
    Name varchar(50),
    AvailableSeats int,
    TotalSeats int
)

create table dbo.Usages
(
    UsageID int primary key,
    Name varchar(50)
)

--If a Usage is Unique to each room I would remove this table and add RoomID to the Usages Table
create table dbo.RoomUsages
(
    UsageID int foreign key (UsageID) references Usages(UsageID),
    RoomID int foreign key (RoomID) references Rooms(RoomID),
    primary key (UsageID, RoomID)
)


create table dbo.TeamTypes
(
    TeamTypeID int primary key,
    Name varchar(50)
)

create table dbo.Teams
(
    TeamID int primary key,
    RoomID int foreign key (RoomID) references Rooms(RoomID),
    TeamTypeID int foreign key (TeamTypeID) references TeamTypes(TeamTypeID),
    Warning varchar(50)
)

--If a Student's room will always be the same as their Team's room I would remove the RoomID column from either Teams or Students 
create table dbo.Students
(
    StudentID int primary key,
    HighSchoolID int foreign key (HighSchoolID) references HighSchools(HighSchoolID),
    TeamID int foreign key (TeamID) references Teams(TeamID),
    RoomID int foreign key (RoomID) references Rooms(RoomID),
    Name varchar(50),
    DOB date,

)

create table dbo.Contests
(
    ContestID int primary key,
    Name varchar(50)
)

create table dbo.ContestTeams
(
    ContestID int foreign key (ContestID) references Contests(ContestID),
    TeamID int foreign key (TeamID) references Teams(TeamID),
    primary key (ContestID, TeamID)
)

數據庫圖