Update mongodb

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

@@ -260,7 +260,8 @@ namespace SqlSugar.MongoDb
                 name = "ToDate";
             if (name == "Contains" && methodCallExpression.Arguments.Count == 1
                 && methodCallExpression?.Object?.Type != null 
-                && typeof(IEnumerable).IsAssignableFrom(methodCallExpression.Object.Type))
+                && typeof(IEnumerable).IsAssignableFrom(methodCallExpression.Object.Type)
+                && methodCallExpression.Object.Type!=UtilConstants.StringType)
             {
                 name = "ContainsArray";
             }

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

@@ -736,6 +736,16 @@ namespace SqlSugar.MongoDb
                 var inDoc = new BsonDocument(name, new BsonDocument("$in", bsonArray));
                 return inDoc.ToJson(UtilMethods.GetJsonWriterSettings());
             }
+            else if (ExpressionTool.GetParameters(itemExp).Count == 0)
+            {
+                // itemExp 是常量表达式，arrayExp 是字段表达式
+                var value =UtilMethods.MyCreate(ExpressionTool.DynamicInvoke(itemExp));
+                BsonValue arrayField = new ExpressionVisitor(context).Visit(arrayExp);
+ 
+                // 构建 MongoDB $in 查询表达式，判断 value 是否在 arrayField 字段数组中
+                var inDoc = new BsonDocument(arrayField.ToString(), new BsonDocument(  "$in",new BsonArray() { value } ));
+                return inDoc.ToJson(UtilMethods.GetJsonWriterSettings());
+            }
             else
             {
                 // 数组表达式不是常量，需生成MongoDB $in表达式，数组字段为arrayExp，判断itemExp是否在数组中

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

@@ -308,7 +308,7 @@ namespace SqlSugar.MongoDb
 
                 // $unwind
                 BsonValue unwindDoc = null;
-                if (item.JoinType == JoinType.Left&&isEasyJoin)
+                if (item.JoinType == JoinType.Left)
                 {
                     unwindDoc = new BsonDocument("$unwind", new BsonDocument
                     {