Update mongodb

Src/Asp.NetCore2/MongoDbTest/UnitTest/QueryWhere.cs

@@ -53,7 +53,9 @@ namespace MongoDbTest
 
             var list5 = db.Queryable<Student>().Where(it =>it.CreateDateTime==DateTime.Now.Date).ToList();
             var list6 = db.Queryable<Student>().Where(it => it.CreateDateTime == DateTime.Now.AddDays(1)).ToList();
-            var list7 = db.Queryable<Student>().Where(it => it.CreateDateTime.Date == DateTime.Now.AddDays(1)).ToList();
+
+            var dt = DateTime.Now.AddDays(-10).Date;
+            var list7 = db.Queryable<Student>().Where(it => it.CreateDateTime.Date == dt).ToList();
         }
 
         private static void ValidateStudentData(SqlSugar.SqlSugarClient db)

Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/BinaryExpressionTranslator/SqlFuncExpression.cs

@@ -62,7 +62,7 @@ namespace SqlSugar.MongoDb
 
             return null;
         }
-        private static readonly List<string> AllowedDateParts = new List<string>()
+        public static readonly List<string> AllowedDateParts = new List<string>()
         {
             "Date", "Year", "Month", "Day", "Hour", "Minute", "Second", "Millisecond"
         };

Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/FieldPathExtractor.cs

@@ -23,11 +23,28 @@ namespace SqlSugar.MongoDb
         {
             var oldExp = expr;
             var oldMember = expr as MemberExpression;
-            if (ExpressionTool.GetParameters(expr).Count == 0) 
+            if (ExpressionTool.GetParameters(expr).Count == 0)
-            { 
+            {
                 var value = ExpressionTool.GetMemberValue(oldMember.Member, oldExp);
                 return BsonValue.Create(value);
-            } 
+            }
+            else if (!string.IsNullOrEmpty(BinaryExpressionTranslator.GetSystemDateMemberName(expr)))
+            {
+               var memberExp= (expr as MemberExpression);
+                var method = new MongoDbMethod() { context = _context };
+                var model = new MethodCallExpressionModel() { Args = new List<MethodCallExpressionArgs>() };
+                if (memberExp.Member.Name == "Date") 
+                {
+                    model.Args.Add(new MethodCallExpressionArgs() { MemberValue = memberExp.Expression });
+                    return method.ToDateShort(model);
+                }
+
+            }
+            return ExtractFieldPath(expr);
+        }
+
+        private BsonValue ExtractFieldPath(Expression expr)
+        {
             var parts = new Stack<string>();
 
             while (expr is MemberExpression member)
@@ -40,7 +57,7 @@ namespace SqlSugar.MongoDb
             {
                 _visitorContext.ExpType = typeof(MemberExpression);
             }
-            if (parts.Count == 1&& expr is ParameterExpression parameter) 
+            if (parts.Count == 1 && expr is ParameterExpression parameter)
             {
                 if (_context?.context != null)
                 {

Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDb/SqlBuilder/MongoDbExpressionContext.cs

@@ -4,6 +4,7 @@ using SqlSugar.MongoDb;
 using System;
 using System.Linq;
 using System.Linq.Expressions;
+using System.Text.RegularExpressions;
 namespace SqlSugar.MongoDb
 {
     public class MongoDbExpressionContext : ExpressionContext, ILambdaExpressions
@@ -292,6 +293,17 @@ namespace SqlSugar.MongoDb
                     { left.ToString(), regexDoc }
                 });
             return match.ToJson(UtilMethods.GetJsonWriterSettings());
+        } 
+        public override string ToDateShort(MethodCallExpressionModel model)
+        {
+            var item = model.Args.First().MemberValue;
+            BsonValue itemValue = new ExpressionVisitor(context).Visit(item as Expression);
+            var dateTruncDoc = new BsonDocument("$dateTrunc", new BsonDocument
+            {
+                { "date", $"${itemValue}" },
+                { "unit", "day" }
+            });
+            return dateTruncDoc.ToJson(UtilMethods.GetJsonWriterSettings());
         }
     }
 }