我在 LINQ - Full Outer Join 找到了这段代码:
var leftOuterJoin = from first in firstNames
join last in lastNames
on first.ID equals last.ID
into temp
from last in temp.DefaultIfEmpty(new { first.ID, Name = default(string) })
select new
{
first.ID,
FirstName = first.Name,
LastName = last.Name,
};
var rightOuterJoin = from last in lastNames
join first in firstNames
on last.ID equals first.ID
into temp
from first in temp.DefaultIfEmpty(new { last.ID, Name = default(string) })
select new
{
last.ID,
FirstName = first.Name,
LastName = last.Name,
};
包含这段代码的答案得到了很多赞成票,但我发现这里有些问题。在左外连接中,它对第二个实体使用 into
和 from
,在右外连接中,它做同样的事情。所以,这两种实现对我来说似乎都是一样的。你能告诉我左外连接和右外连接的区别吗?提前致谢。
编辑:
我认为右外连接应该是这样的:
var rightOuterJoin = from first in firstNames
join last in lastNames
on first.ID equals last.ID
into temp
from first in temp.DefaultIfEmpty(new { last.ID, Name = default(string) })
select new
{
last.ID,
FirstName = first.Name,
LastName = last.Name,
};
最佳答案
关于c# - LINQ中左外连接和右外连接的实现区别,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/43966023/