-

Src/Asp.Net/SqlServerTest/Demos/1_Query.cs

@@ -41,6 +41,15 @@ namespace OrmTest.Demo
         {
             var db = GetInstance();
             var i = 0;
+
+
+            var sumflat2num = db.Queryable<Student, Student>((s1, s2) => 
+            new object[] { JoinType.Left, s1.Id == s2.Id })
+ 
+            .Select((s1, s2) => new Student
+            {  Id = SqlFunc.IsNull(SqlFunc.AggregateSum(SqlFunc.IIF(s1.Id ==1, s1.Id, s1.Id * -1)), 0) })
+            .First();
+
             var getAll11 = db.Queryable<Student>().Where(it => SqlFunc.Subqueryable<School>().Where(s => s.Id == it.Id).Max(s=>s.Id)==i).ToList();
             var getAll12 = db.Queryable<Student>().Where(it => SqlFunc.Subqueryable<School>().Where(s => s.Id == it.Id).Max(s => s.Id) == 1).ToList();
             var getAll7 = db.Queryable<Student>().Where(it => SqlFunc.Subqueryable<School>().Where(s => s.Id == it.Id).Any()).ToList();

Src/Asp.Net/SqlSugar/ExpressionsToSql/ResolveItems/BaseResolve.cs

@@ -256,6 +256,7 @@ namespace SqlSugar
             newContext.MappingColumns = this.Context.MappingColumns;
             newContext.MappingTables = this.Context.MappingTables;
             newContext.IgnoreComumnList = this.Context.IgnoreComumnList;
+            newContext.IsSingle = this.Context.IsSingle;
             newContext.SqlFuncServices = this.Context.SqlFuncServices;
             newContext.Resolve(item, this.Context.IsJoin ? ResolveExpressType.WhereMultiple : ResolveExpressType.WhereSingle);
             this.Context.Index = newContext.Index;