Add demo

Src/Asp.NetCore2/SqlSeverTest/UserTestCases/UnitTest/Main.cs

@@ -1,4 +1,5 @@
 using Demo;
+using SqlSeverTest;
 using SqlSeverTest.UserTestCases;
 using SqlSeverTest.UserTestCases.UnitTest;
 using SqlSugar;
@@ -33,6 +34,7 @@ namespace OrmTest
         }
         public static void Init()
         {
+            Unitdasfyasdfa.Init();
             Unitafdssfasydsfsf.Init();
             Unitsdfadysdfa.Init();
             Unitadfasdysdfa.Init();

Src/Asp.NetCore2/SqlSeverTest/UserTestCases/UnitTest/Unitsdfasdfysfs.cs

@@ -0,0 +1,58 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace SqlSeverTest 
+{
+    using OrmTest;
+    using SqlSugar;
+    using System;
+    using System.Collections.Generic;
+
+    public class DummyModel
+    {
+        public string FieldA { get; set; }
+        public string FieldB { get; set; }
+        public string FieldC { get; set; }
+        public string FieldD { get; set; }
+    }
+
+    public class SourceEntity
+    {
+        public string FieldA { get; set; }
+        public string FieldB { get; set; }
+        public string FieldC { get; set; }
+        public string FieldD { get; set; }
+    }
+
+   public  class Unitdasfyasdfa
+    {
+       public static void Init()
+        {
+            var db = NewUnitTest.Db;
+            int groupLevel = 2;
+            db.CodeFirst.InitTables<SourceEntity>();
+            var queryAble = db.Queryable<SourceEntity>();
+
+            var result = queryAble
+                .GroupBy((a) => new
+                {
+                    a.FieldA,
+                    a.FieldB,
+                    a.FieldC,
+                    FieldD = SqlFunc.IIF(groupLevel > 1, a.FieldD, "NA")
+                })
+                .Select(a => new DummyModel
+                {
+                    FieldA = a.FieldA,
+                    FieldB = a.FieldB,
+                    FieldC = a.FieldC,
+                    FieldD = SqlFunc.IIF(groupLevel > 1, a.FieldD, "NA")
+                })
+                .ToList();
+        }
+    }
+
+}