Update exp to sql

Src/Asp.Net/SqlServerTest/Demo/Demo1_Queryable.cs

@@ -124,6 +124,11 @@ namespace OrmTest
                 customName2 = SqlFunc.Subqueryable<Custom>().Where("it.CustomId = id").Where(s => true).Select(s => s.Name)
             }).ToList();
 
+            var list1 = db.Queryable<Order>().Select(it => new
+            {
+                id = SqlFunc.Subqueryable<Custom>().Where(s => s.Id == 1).Sum(s => s.Id) * 1
+            }).ToList();
+
             var list2 = db.Queryable<Order>().Where(it =>
             SqlFunc.Subqueryable<OrderItem>() 
              .LeftJoin<OrderItem>((i,y)=>i.ItemId==y.ItemId)

Src/Asp.Net/SqlSugar/Abstract/SqlBuilderProvider/QueryBuilder.cs

@@ -238,6 +238,7 @@ namespace SqlSugar
             {
                 resolveExpress.PgSqlIsAutoToLower = true;
             }
+            resolveExpress.RootExpression = expression;
             resolveExpress.JoinQueryInfos = Builder.QueryBuilder.JoinQueryInfos;
             resolveExpress.IsSingle = IsSingle();
             resolveExpress.MappingColumns = Context.MappingColumns;

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

@@ -45,6 +45,7 @@ namespace SqlSugar
         public IgnoreColumnList IgnoreComumnList { get; set; }
         public bool PgSqlIsAutoToLower { get; set; }
         public List<SqlFuncExternal> SqlFuncServices { get; set; }
+        public Expression RootExpression { get; set; }
         public bool IsSingle
         {
             get
@@ -129,6 +130,7 @@ namespace SqlSugar
             copyContext.ParameterIndex = this.ParameterIndex;
             copyContext.PgSqlIsAutoToLower = this.PgSqlIsAutoToLower;
             copyContext.IsSingle = this.IsSingle;
+            copyContext.RootExpression = this.RootExpression;
             return copyContext;
         }
         public ExpressionContext GetCopyContextWithMapping()
@@ -144,6 +146,7 @@ namespace SqlSugar
             copyContext.RefreshMapping = this.RefreshMapping;
             copyContext.PgSqlIsAutoToLower = this.PgSqlIsAutoToLower;
             copyContext.IsSingle = this.IsSingle;
+            copyContext.RootExpression = this.RootExpression;
             return copyContext;
         }
         #endregion

Src/Asp.Net/SqlSugar/ExpressionsToSql/Subquery/SubResolve.cs

@@ -63,6 +63,11 @@ namespace SqlSugar
                         context.SingleTableNameSubqueryShortName = (((meExp.Body as BinaryExpression).Right as MemberExpression).Expression as ParameterExpression).Name;
                     }
                 }
+                else if (context.RootExpression!=null&&context.Expression.GetType().Name == "SimpleBinaryExpression")
+                {
+                    var name = (this.context.RootExpression as LambdaExpression).Parameters[0].Name;
+                    context.SingleTableNameSubqueryShortName = name;
+                }
                 else
                 {
                     Check.Exception(true, "I'm sorry I can't parse the current expression");

Src/Asp.Net/SqlSugar/Interface/ILambdaExpressions.cs

@@ -27,6 +27,7 @@ namespace SqlSugar
          Action<Type> InitMappingInfo { get; set; }
          Action RefreshMapping { get; set; }
         bool PgSqlIsAutoToLower { get; set; }
+        Expression RootExpression { get; set; }
 
         string GetAsString(string fieldName, string fieldValue);
         void Resolve(Expression expression, ResolveExpressType resolveType);