linq lambda left join

//var list = table1.Join(table2, ee => ee.Id, ff => ff.table1_Id, (ee, ff) => new { ee, ff }).DefaultIfEmpty(); //只能实现inner join

left join例子:

TUsers.GroupJoin(
TUserInfo,
u => u.UserID,
ui => ui.UserID,
(u, ui) => new { u, ui }).Select(o => o)

right join 将TUsers和TUserInfo换个位置.

http://stackoverflow.com/questions/584820/how-do-you-perform-a-left-outer-join-using-linq-extension-methods?noredirect=1

var qry = Foo.GroupJoin(

          Bar,

          foo => foo.Foo_Id,

          bar => bar.Foo_Id,

          (x,y) => new { Foo = x, Bars = y })

    .SelectMany(

          x => x.Bars.DefaultIfEmpty(),

          (x,y) => new { Foo=x.Foo, Bar=y});

From:http://www.cnblogs.com/xuejianxiyang/p/6149964.html

巴特西

linq lambda left join

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