mcs/tests/gtest-linq-10.cs

   1
   2
   3 using System;
   4 using System.Collections.Generic;
   5 using System.Linq;
   6
   7 class DataA
   8 {
   9         public int Key;
  10         public string Text;
  11 }
  12
  13 class DataB
  14 {
  15         public int Key;
  16         public string Value;
  17 }
  18
  19 class GroupJoin
  20 {
  21         public static int Main ()
  22         {
  23                 DataA[] d1 = new DataA[] { new DataA () { Key = 1, Text = "Foo" }};
  24                 DataB[] d2 = new DataB[] { new DataB () { Key = 2, Value = "Second" }};
  25
  26                 var e = from a in d1
  27                         join b in d2 on a.Key equals b.Key into ab
  28                         from x in ab.DefaultIfEmpty ()
  29                         select new { a = x == default (DataB) ? "<empty>" : x.Value, b = a.Text };
  30
  31                 var res = e.ToList ();
  32                 if (res.Count != 1)
  33                         return 1;
  34
  35                 if (res [0].a != "<empty>")
  36                         return 2;
  37
  38                 if (res [0].b != "Foo")
  39                         return 3;
  40
  41                 // Explicitly typed
  42                 e = from a in d1
  43                         join DataB b in d2 on a.Key equals b.Key into ab
  44                         from x in ab.DefaultIfEmpty ()
  45                         select new { a = x == default (DataB) ? "<empty>" : x.Value, b = a.Text };
  46
  47                 foreach (var o in e)
  48                         Console.WriteLine (o);
  49
  50                 res = e.ToList ();
  51                 if (res.Count != 1)
  52                         return 10;
  53
  54                 if (res [0].a != "<empty>")
  55                         return 11;
  56
  57                 if (res [0].b != "Foo")
  58                         return 12;
  59
  60                 var e2 = from a in d1
  61                         join a in d2 on a.Key equals a.Key into ab
  62                         select a;
  63
  64                 Console.WriteLine ("OK");
  65                 return 0;
  66         }
  67 }
  68