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[英]How to seed the database with a many-to-many relationship in Entity Code First
[英]Seed Code First Many-to-Many off of a Many-to-Many
我正在使用代码优先方法使用Entity Framework。 我已经为多对多关系(类型到状态)成功地播种了数据。 现在,我需要为状态和SubStatus之间的多对多关系植入数据。
首先创建所有状态,然后添加每个类型,并为每个状态添加多对多关系。
这是我的类型和状态信息:
IList<Status> statuses = new List<Status>();
statuses .Add(new Status() { Value = "On" });
statuses .Add(new Status() { Value = "Off" });
foreach (Status s in statuses)
{
context.Set<Status>().AddOrUpdate(s);
}
Type type1 = new Type()
{
Value = "Type 1",
Status = new List<Status>()
{
statuses.FirstOrDefault(e => e.Value == "On"),
statuses.FirstOrDefault(e => e.Value == "Off")
}
};
Type type2 = new Type()
{
Value = "Type 2",
Status = new List<Status>()
{
statuses.FirstOrDefault(e => e.Value == "On"),
}
};
我如何以此为基础,现在就可以在Status和SubStatus之间添加多对多关系?
以下是几个SubStatuses的列表:
IList<SubStatus> subStatuses = new List<SubStatus>();
subStatuses.Add(new SubStatus() { Value = "Success" });
subStatuses.Add(new SubStatus() { Value = "Fail" });
foreach (SubStatus s in subStatuses)
{
context.Set<SubStatus>().AddOrUpdate(s);
}
我相信您正在寻找父母/子女关系? 您可以像这样重组您的Status
实体并删除SubSatus
类:
public class Type
{
public string Value {get;set;}
public ICollection<Status> Statuses {get;set;}
{
public class Status
{
public string Value {get;set;}
public int? ParentStatusId {get;set;}
public Status ParentStatus {get;set;}
public ICollection<Status> ChildStatuses {get;set;}
Public ICollection<Type> Types {get;set;}
}
然后,您可以追加ChildStatuses
并将它们与ParentStatus
关联
var typeA = new Type()
{
Value = "Type A"
};
var typeB = new Type()
{
Value = "Type B"
};
var statuses = new List<Status>(){
new Status()
{
Value = "On",
ChildStatuses = new List<Status>(){
new Status()
{
Value = "Success",
Types = new List<Type>()
{
typeA,
typeB
}
},
new Status()
{
Value = "Fail",
Types = new List<Type>()
{
typeB
}
}
}
};
context.Set<Status>().AddOrUpdate(s => s.Value, statuses.ToArray() );
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