diff --git a/Src/Asp.NetCore2/MongoDbTest/ExpTest.cs b/Src/Asp.NetCore2/MongoDbTest/ExpTest.cs
index 8e31d3f45..ca19c5988 100644
--- a/Src/Asp.NetCore2/MongoDbTest/ExpTest.cs
+++ b/Src/Asp.NetCore2/MongoDbTest/ExpTest.cs
@@ -1,5 +1,4 @@
-using Npgsql;
-using SqlSugar.MongoDbCore;
+using SqlSugar.MongoDb;
 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
diff --git a/Src/Asp.NetCore2/MongoDbTest/OrmTest/Models/Order.cs b/Src/Asp.NetCore2/MongoDbTest/OrmTest/Models/Order.cs
index 2e09d35a2..4ce2290a3 100644
--- a/Src/Asp.NetCore2/MongoDbTest/OrmTest/Models/Order.cs
+++ b/Src/Asp.NetCore2/MongoDbTest/OrmTest/Models/Order.cs
@@ -1,5 +1,5 @@
 using SqlSugar;
-using SqlSugar.MongoDbCore;
+using SqlSugar.MongoDb;
 using System;
 using System.Collections.Generic;
 using System.Linq;
diff --git a/Src/Asp.NetCore2/MongoDbTest/OrmTest/Models/OrderItem.cs b/Src/Asp.NetCore2/MongoDbTest/OrmTest/Models/OrderItem.cs
index 6d96560bd..7b71c6ef9 100644
--- a/Src/Asp.NetCore2/MongoDbTest/OrmTest/Models/OrderItem.cs
+++ b/Src/Asp.NetCore2/MongoDbTest/OrmTest/Models/OrderItem.cs
@@ -1,4 +1,4 @@
-using SqlSugar.MongoDbCore;
+using SqlSugar.MongoDb;
 using System;
 using System.Collections.Generic;
 using System.Linq;
diff --git a/Src/Asp.NetCore2/MongoDbTest/OrmTest/OrmTest.cs b/Src/Asp.NetCore2/MongoDbTest/OrmTest/OrmTest.cs
index 4dfc79d1a..a80056947 100644
--- a/Src/Asp.NetCore2/MongoDbTest/OrmTest/OrmTest.cs
+++ b/Src/Asp.NetCore2/MongoDbTest/OrmTest/OrmTest.cs
@@ -76,7 +76,7 @@ namespace MongoDbTest
             .ExecuteCommand();
 
             var delrow3 = db.Deleteable<OrderInfo>()
-           .Where(it=>it.Id==ids.Last()||it.Name=="A1")
+           .Where(it=>it.Id==ids.Last() )
            .ExecuteCommand();
 
             var list = db.Queryable<OrderInfo>().ToDataTable();
@@ -103,13 +103,20 @@ namespace MongoDbTest
                    Name=it.Name
                 }).ToDataTable();
 
-            var list11 = db.Queryable<OrderInfo>()
-                .Select(it => new
-                {
-                    Id = it.Id,
-                    Name = it.Name
-                }).ToDataTable();
+            var list11 = db.Queryable<OrderInfo>() 
+                            .Select(it => new
+                            {
+                                Id = it.Id,
+                                Name = it.Name
+                            }).ToList();
 
+            var list12 = db.Queryable<OrderInfo>()
+                       .Select(it => new
+                       {
+                           Id = it.Id,
+                           Name = it.Name+"b",
+                           Name2 =   "b"+it.Name
+                       }).ToDataTable(); 
             //测试生成SQL性能
             TestSqlBuilder(db);
         }
diff --git a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/Context/ExpressionVisitorContext.cs b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/Context/ExpressionVisitorContext.cs
index f78357ac7..e9b9ba6a3 100644
--- a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/Context/ExpressionVisitorContext.cs
+++ b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/Context/ExpressionVisitorContext.cs
@@ -2,7 +2,7 @@
 using System.Collections.Generic;
 using System.Text;
 
-namespace SqlSugar.MongoDbCore 
+namespace SqlSugar.MongoDb  
 {
     public class ExpressionVisitorContext
     {
diff --git a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/Context/MongoNestedTranslatorContext.cs b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/Context/MongoNestedTranslatorContext.cs
index 48f34a174..0e2e848b6 100644
--- a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/Context/MongoNestedTranslatorContext.cs
+++ b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/Context/MongoNestedTranslatorContext.cs
@@ -2,7 +2,7 @@
 using System.Collections.Generic;
 using System.Text;
 
-namespace SqlSugar.MongoDbCore
+namespace SqlSugar.MongoDb 
 {
     public class MongoNestedTranslatorContext
     {
diff --git a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/ExpressionVisitor.cs b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/ExpressionVisitor.cs
index 39bd1bfc2..791093110 100644
--- a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/ExpressionVisitor.cs
+++ b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/ExpressionVisitor.cs
@@ -6,7 +6,7 @@ using System.Data;
 using System.Linq.Expressions;
 using System.Text;
 
-namespace SqlSugar.MongoDbCore 
+namespace SqlSugar.MongoDb 
 {
     public class ExpressionVisitor
     {
diff --git a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/MongoDbExpTools.cs b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/MongoDbExpTools.cs
index 4b2169c64..6df4ee968 100644
--- a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/MongoDbExpTools.cs
+++ b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/MongoDbExpTools.cs
@@ -4,7 +4,7 @@ using System.Globalization;
 using System.Linq.Expressions;
 using System.Text;
 
-namespace SqlSugar.MongoDbCore 
+namespace SqlSugar.MongoDb 
 {
     public class MongoDbExpTools
     { 
diff --git a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/MongoNestedTranslator.cs b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/MongoNestedTranslator.cs
index 3f0eaabd4..a94dac909 100644
--- a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/MongoNestedTranslator.cs
+++ b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/MongoNestedTranslator.cs
@@ -5,7 +5,7 @@ using System.Linq.Expressions;
 using Newtonsoft.Json.Linq;
 using MongoDB.Bson;
 
-namespace SqlSugar.MongoDbCore 
+namespace SqlSugar.MongoDb 
 { 
     public static class MongoNestedTranslator
     {
diff --git a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/BinaryExpressionTranslator.cs b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/BinaryExpressionTranslator.cs
index 5902953d5..fe5ae6f2a 100644
--- a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/BinaryExpressionTranslator.cs
+++ b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/BinaryExpressionTranslator.cs
@@ -1,4 +1,5 @@
-using MongoDB.Bson;
+using Dm.parser;
+using MongoDB.Bson;
 using MongoDB.Driver;
 using Newtonsoft.Json.Linq;
 using System;
@@ -7,7 +8,7 @@ using System.Linq;
 using System.Linq.Expressions;
 using System.Text;
 
-namespace SqlSugar.MongoDbCore
+namespace SqlSugar.MongoDb
 {
     public class BinaryExpressionTranslator
     {
@@ -63,7 +64,7 @@ namespace SqlSugar.MongoDbCore
             OutParameters(expr, out field, out value, out leftIsMember, out rightIsMember, out op);
             if (op == null)
             {
-                return GetCalculationOperation(field, expr.NodeType, value);
+                return GetCalculationOperation(field, expr.NodeType, value,leftIsMember, rightIsMember);
             }
             else
             {
@@ -127,7 +128,7 @@ namespace SqlSugar.MongoDbCore
                         if (_context?.context != null)
                         {
                             var entityInfo = _context.context.EntityMaintenance.GetEntityInfo(parameter.Type);
-                            var columnInfo = entityInfo.Columns.FirstOrDefault(s => s.PropertyName == leftValue);
+                            var columnInfo = entityInfo.Columns.FirstOrDefault(s => s.PropertyName == leftValue||s.DbColumnName==leftValue);
                             if (columnInfo != null)
                             {
                                 leftValue = columnInfo.DbColumnName;
@@ -139,7 +140,17 @@ namespace SqlSugar.MongoDbCore
                         }
                     }
                 }
-                return new BsonDocument { { leftValue, rightValue } };
+                if (op == "$eq")
+                {
+                    return new BsonDocument { { leftValue, rightValue } };
+                }
+                else 
+                {
+                    return new BsonDocument
+                    {
+                        { leftValue, new BsonDocument { { op, rightValue } } }
+                    };
+                }
             }
             else
             {
@@ -150,7 +161,7 @@ namespace SqlSugar.MongoDbCore
             }
         }
 
-        private BsonDocument GetCalculationOperation(BsonValue field, ExpressionType nodeType, BsonValue value)
+        private BsonDocument GetCalculationOperation(BsonValue field, ExpressionType nodeType, BsonValue value, bool leftIsMember, bool rightIsMember)
         {
             string operation = nodeType switch
             {
@@ -161,11 +172,19 @@ namespace SqlSugar.MongoDbCore
                 ExpressionType.Modulo => "$mod",
                 _ => throw new NotSupportedException($"Unsupported calculation operation: {nodeType}")
             };
-
+            if (operation == "$add"&& value.BsonType==BsonType.String) 
+            {
+                operation = "$concat"; 
+                return new BsonDocument
+                {
+                    { operation, new BsonArray { UtilMethods.GetBsonValue(leftIsMember, field), UtilMethods.GetBsonValue(rightIsMember, value) } }
+                };
+                ;
+            }
             return new BsonDocument
-    {
-        { field.ToString(), new BsonDocument { { operation, value } } }
-    };
+            {
+                { field.ToString(), new BsonDocument { { operation, value } } }
+            };
         }
 
         private static bool IsRightValue(bool leftIsMember, bool rightIsMember, string op)
diff --git a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/FieldPathExtractor.cs b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/FieldPathExtractor.cs
index f91283279..156ec0cc9 100644
--- a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/FieldPathExtractor.cs
+++ b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/FieldPathExtractor.cs
@@ -6,7 +6,7 @@ using System.Linq;
 using System.Linq.Expressions;
 using System.Text;
 
-namespace SqlSugar.MongoDbCore
+namespace SqlSugar.MongoDb
 {
     public class FieldPathExtractor
     {
diff --git a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/MemberInitExpressionTractor.cs b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/MemberInitExpressionTractor.cs
index 185e6a59b..9728354fd 100644
--- a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/MemberInitExpressionTractor.cs
+++ b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/MemberInitExpressionTractor.cs
@@ -5,7 +5,7 @@ using System.Linq;
 using System.Linq.Expressions;
 using System.Text;
 
-namespace SqlSugar.MongoDbCore 
+namespace SqlSugar.MongoDb 
 {
     public class MemberInitExpressionTractor 
     {
diff --git a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/MethodCallExpressionTractor.cs b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/MethodCallExpressionTractor.cs
index fa7fe1d6b..400e77e06 100644
--- a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/MethodCallExpressionTractor.cs
+++ b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/MethodCallExpressionTractor.cs
@@ -4,7 +4,7 @@ using System.Collections.Generic;
 using System.Linq.Expressions;
 using System.Text;
 
-namespace SqlSugar.MongoDbCore 
+namespace SqlSugar.MongoDb 
 {
     public class MethodCallExpressionTractor
     {
diff --git a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/NewExpressionTranslator.cs b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/NewExpressionTranslator.cs
index 75bea11b6..2a4568aaa 100644
--- a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/NewExpressionTranslator.cs
+++ b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/NewExpressionTranslator.cs
@@ -3,7 +3,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq.Expressions;
 
-namespace SqlSugar.MongoDbCore
+namespace SqlSugar.MongoDb 
 {
     public class NewExpressionTractor
     {
@@ -44,13 +44,25 @@ namespace SqlSugar.MongoDbCore
                 // 使用 ExpressionVisitor 访问表达式
                 var json = new ExpressionVisitor(_context, _visitorContext).Visit(exp.Arguments[exp.Members.IndexOf(member)]);
 
-                // 构建 MongoDB 的投影文档
-                projectionDocument[fieldName] = "$" + json.ToString();
+                SetProjectionValue(json, fieldName, projectionDocument);
             }
             projectionDocument["_id"] = 0;
             return projectionDocument;
         }
 
+        private static void SetProjectionValue(BsonValue json, string fieldName, BsonDocument projectionDocument)
+        {
+            var jsonString = json.ToJson(UtilMethods.GetJsonWriterSettings());
+            if (jsonString.StartsWith("{") && jsonString.EndsWith("}"))
+            {
+                projectionDocument[fieldName] = json;
+            }
+            else
+            {
+                projectionDocument[fieldName] = "$"+jsonString.TrimStart('\"').TrimEnd('\"');
+            }
+        }
+
         private BsonValue Update(Expression expr)
         {
             var exp = expr as NewExpression ?? throw new InvalidOperationException("Expression must be NewExpression");
diff --git a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/ValueExtractor.cs b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/ValueExtractor.cs
index 947ff9407..47ea42c54 100644
--- a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/ValueExtractor.cs
+++ b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/ValueExtractor.cs
@@ -5,7 +5,7 @@ using System.Collections.Generic;
 using System.Linq.Expressions;
 using System.Text;
 
-namespace SqlSugar.MongoDbCore 
+namespace SqlSugar.MongoDb 
 {
     public class ValueExtractor
     {
diff --git a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDb/MongoDbProvider.cs b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDb/MongoDbProvider.cs
index 09cdead4d..f3e62550b 100644
--- a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDb/MongoDbProvider.cs
+++ b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDb/MongoDbProvider.cs
@@ -1,6 +1,6 @@
 using Microsoft.Data.SqlClient;
 using MongoDb.Ado.data;
-using SqlSugar.MongoDbCore;
+using SqlSugar.MongoDb;
 using System;
 using System.Collections.Generic;
 using System.Data;
diff --git a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDb/SqlBuilder/MongoDbExpressionContext.cs b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDb/SqlBuilder/MongoDbExpressionContext.cs
index 578de1463..fa2fa0429 100644
--- a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDb/SqlBuilder/MongoDbExpressionContext.cs
+++ b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDb/SqlBuilder/MongoDbExpressionContext.cs
@@ -1,6 +1,6 @@
 using MongoDB.Bson.IO;
 using MongoDB.Bson;
-using SqlSugar.MongoDbCore;
+using SqlSugar.MongoDb;
 using System;
 using System.Linq;
 using System.Linq.Expressions;
diff --git a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDb/SqlBuilder/MongoDbQueryBuilder.cs b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDb/SqlBuilder/MongoDbQueryBuilder.cs
index 16f7cfc78..2896ad617 100644
--- a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDb/SqlBuilder/MongoDbQueryBuilder.cs
+++ b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDb/SqlBuilder/MongoDbQueryBuilder.cs
@@ -1,5 +1,5 @@
 using MongoDB.Bson;
-using SqlSugar.MongoDbCore;
+using SqlSugar.MongoDb;
 using System;
 using System.Collections.Generic;
 using System.Linq;
diff --git a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDb/SqlSugarMongoDbDataAdapter.cs b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDb/SqlSugarMongoDbDataAdapter.cs
index 998cfa6bc..c2028d800 100644
--- a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDb/SqlSugarMongoDbDataAdapter.cs
+++ b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDb/SqlSugarMongoDbDataAdapter.cs
@@ -3,7 +3,7 @@ using System;
 using System.Collections.Generic;
 using System.Text;
 
-namespace SqlSugar.MongoDbCore 
+namespace SqlSugar.MongoDb 
 {
     public class SqlSugarMongoDbDataAdapter : MongoDbDataAdapter, SqlSugar.IDataAdapter 
     {
diff --git a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDbBase.cs b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDbBase.cs
index 5e3fa19e2..88880703a 100644
--- a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDbBase.cs
+++ b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDbBase.cs
@@ -2,7 +2,7 @@
 using System.Collections.Generic;
 using System.Text;
 
-namespace SqlSugar.MongoDbCore
+namespace SqlSugar.MongoDb
 {
     public class MongoDbBase
     {
diff --git a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/Tools/UtilMethods.cs b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/Tools/UtilMethods.cs
index f57abef5c..e1ddc33c4 100644
--- a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/Tools/UtilMethods.cs
+++ b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/Tools/UtilMethods.cs
@@ -1,4 +1,5 @@
-using System;
+using MongoDB.Bson;
+using System;
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Data;
@@ -471,6 +472,13 @@ namespace SqlSugar.MongoDb
             }
             return dic;
         }
+
+        internal static BsonValue GetBsonValue(bool isMember, BsonValue field)
+        {
+            if (isMember) return "$" + field;
+            else
+                return field;
+        }
         //public static object ConvertDataByTypeName(string ctypename,string value)
         //{
         //    var item = new ConditionalModel() {