一对多的外键太多

Question

此问题类似于：

为一对多关系编写第一个多个外键代码

和

实体框架代码优先-来自同一表的两个外键

但是还不足够让我寻求解决方案。

我有一个“团队”模型，其中一个外键指向另一个名为“房间”的模型，一个团队只能有一个房间。 房间模型有两个团队“ p2teams”和“ p3teams”列表。 实际上，在teams表中，它为房间创建了三个不同的id列：“ RoomID”，“ Room_RoomID”和“ Room_RoomID1”。

这导致我尝试设置团队的房间（例如exampleTeam.Room = exampleRoom），并且只影响RoomID列，而不影响其余部分。 此外，我只是真的不完全了解发生这种情况的结果。

以下是我的模型，数据库图以及团队表中的一些示例数据。 谢谢您的帮助！

团队模式：

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; }
}

房间型号：

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; }
}

相关数据库图图像

球队前几行表格

再次感谢您的所有帮助。

Answer 1

实体框架行为正常。 如果设置“团队室”属性，则只会影响该表中的RoomID 。 其他列在“房间”表中更改。

您的房间表应该只有一个ICollection<Team> 。 如果您希望一个房间有多个团队列表， TeamTypeID向“团队”表中添加一个TeamTypeID 。 这样，一个会议室可以拥有与TeamTypes一样多的团队列表。

因为您在“房间”表中有多个ICollection<Team> ，所以正在“团队”表中生成其他列。

基于很多假设，我认为这两个类应该看起来像

球队：

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; }
}

房间：

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; }
}

我已经创建了一个脚本来创建数据库表，并相信该脚本将基于更多的假设来实现您的目标：

• 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码，则可以使用Entity Framework从这些表中生成Code First类。

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)
)

数据库图