Update exp to sql

Src/Asp.Net/SqlServerTest/SqlServerTest.csproj

@@ -92,6 +92,7 @@
     <Compile Include="_OldTest\BugTest\BugModels\TStock.cs" />
     <Compile Include="_OldTest\BugTest\BugModels\TTempStock.cs" />
     <Compile Include="_OldTest\BugTest\BugModels\VMaterialInfo.cs" />
+    <Compile Include="_OldTest\BugTest\Bug3t.cs" />
     <Compile Include="_OldTest\Demos\H_Queue.cs" />
     <Compile Include="_OldTest\Demos\I_InsertOrUpdate.cs" />
     <Compile Include="_OldTest\Demos\J_Debugger.cs" />

Src/Asp.Net/SqlServerTest/_OldTest/BugTest/Bug3t.cs

@@ -0,0 +1,46 @@
+using SqlSugar;
+using System;
+using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace OrmTest.Test
+{
+    public class BugTest
+    {
+        public static void Init()
+        {
+            SqlSugarClient Db = new SqlSugarClient(new ConnectionConfig()
+            {
+                ConnectionString = Config.ConnectionString,
+                DbType = DbType.SqlServer,
+                IsAutoCloseConnection = true,
+                //MoreSettings = new ConnMoreSettings()
+                //{
+                //    PgSqlIsAutoToLower = true //我们这里需要设置为false
+                //},
+                InitKeyType = InitKeyType.Attribute,
+            });
+            //调式代码 用来打印SQL 
+            Db.Aop.OnLogExecuting = (sql, pars) =>
+            {
+                Console.WriteLine(sql);
+            };
+
+            var list2 = Db.Queryable<Order, OrderItem, Custom>((o, i, c) => new JoinQueryInfos(
+              JoinType.Left, o.Id == i.OrderId,
+              JoinType.Left, c.Id == o.CustomId
+             ))
+            .Select((o,i,c) => new Order
+            {
+             Id=SqlFunc.IsNull(
+             SqlFunc.Subqueryable<Order>().Where(f=>f.CreateTime>Convert.ToDateTime( o.CreateTime.AddDays(-1))  ).Select(f => f.Id)    
+             ,-1)    
+            }).ToList();
+        }
+    }
+   
+
+}

Src/Asp.Net/SqlSugar/ExpressionsToSql/ExpressionContext.cs

@@ -127,6 +127,7 @@ namespace SqlSugar
             copyContext.RefreshMapping = this.RefreshMapping;
             copyContext.ParameterIndex = this.ParameterIndex;
             copyContext.PgSqlIsAutoToLower = this.PgSqlIsAutoToLower;
+            copyContext.IsSingle = this.IsSingle;
             return copyContext;
         }
         public ExpressionContext GetCopyContextWithMapping()
@@ -141,6 +142,7 @@ namespace SqlSugar
             copyContext.InitMappingInfo = this.InitMappingInfo;
             copyContext.RefreshMapping = this.RefreshMapping;
             copyContext.PgSqlIsAutoToLower = this.PgSqlIsAutoToLower;
+            copyContext.IsSingle = this.IsSingle;
             return copyContext;
         }
         #endregion