我有以下类:转换列表字典
public class Header
{
public int Id { get; set; }
....
}
public class Item
{
public int Id { get; set; }
public int HeaderId { get; set; } //FK
public int ItemSequence { get; set; }
public string Value { get; set; }
...
}
Header
和Item
有一个一对多的关系(每个Header
有很多Items
我有以下Items
:
{{Id=1, HeaderId=1, ItemSequence =1, Value="A"},
{Id=2, HeaderId=1, ItemSequence =2, Value="B"},
{Id=3, HeaderId=2, ItemSequence =1, Value="C"},
{Id=4, HeaderId=2, ItemSequence =2, Value="D"},
{Id=5, HeaderId=2, ItemSequence =3, Value="B"}}
我想写一个查询来查找字典,关键是每个的第一个(ItemSequence
= 1)和值是其它ItemSequence
的价值观,在其它字我想达到以下结果:
Key: {HeaderId=1, ItemSequence =1} , Values : {"A","B"}
Key: {HeaderId=2, ItemSequence =1} , Values : {"C","D","B"}
我写以下查询:
var result = ctx.Headers
.SelectMany(x => x.Items
.Select(t => new { t.Id,t.ItemSequence,t.HeaderId}))
.?
哪些代码我应该使用?
?