diff --git a/Src/Asp.Net/SqlSugar/Abstract/SqlBuilderProvider/SqlBuilderProvider.cs b/Src/Asp.Net/SqlSugar/Abstract/SqlBuilderProvider/SqlBuilderProvider.cs
index 81afc0085..8b05bba33 100644
--- a/Src/Asp.Net/SqlSugar/Abstract/SqlBuilderProvider/SqlBuilderProvider.cs
+++ b/Src/Asp.Net/SqlSugar/Abstract/SqlBuilderProvider/SqlBuilderProvider.cs
@@ -363,6 +363,10 @@ namespace SqlSugar
         {
             return sql;
         }
+        public virtual Type GetNullType(string tableName,string columnName) 
+        {
+            return null;
+        }
         private void BuilderTree(StringBuilder builder,ConditionalTree item,ref  int indexTree, List<SugarParameter>  parameters,ref int mainIndex)
         {
            var conditionals = ToConditionalCollections(item,ref indexTree, parameters);
diff --git a/Src/Asp.Net/SqlSugar/Interface/ISqlBuilder.cs b/Src/Asp.Net/SqlSugar/Interface/ISqlBuilder.cs
index 50c4f249b..37642f870 100644
--- a/Src/Asp.Net/SqlSugar/Interface/ISqlBuilder.cs
+++ b/Src/Asp.Net/SqlSugar/Interface/ISqlBuilder.cs
@@ -42,5 +42,6 @@ namespace SqlSugar
         void RepairReplicationParameters(ref string appendSql, SugarParameter[] parameters, int addIndex);
         KeyValuePair<string, SugarParameter[]> ConditionalModelToSql(List<IConditionalModel> models, int beginIndex = 0);
         string GetUnionFomatSql(string sql);
+        Type GetNullType(string tableName,string columnName);
     }
 }
diff --git a/Src/Asp.Net/SqlSugar/Realization/PostgreSQL/SqlBuilder/PostgreSQLBuilder.cs b/Src/Asp.Net/SqlSugar/Realization/PostgreSQL/SqlBuilder/PostgreSQLBuilder.cs
index fef7d4b78..53f8dd2eb 100644
--- a/Src/Asp.Net/SqlSugar/Realization/PostgreSQL/SqlBuilder/PostgreSQLBuilder.cs
+++ b/Src/Asp.Net/SqlSugar/Realization/PostgreSQL/SqlBuilder/PostgreSQLBuilder.cs
@@ -102,5 +102,21 @@ namespace SqlSugar
         {
             return " ( " + sql + " )  ";
         }
+
+        public override Type GetNullType(string tableName, string columnName) 
+        {
+            var columnInfo=this.Context.DbMaintenance.GetColumnInfosByTableName(tableName).FirstOrDefault(z => z.DbColumnName.EqualCase(columnName));
+            if (columnInfo != null) 
+            {
+                var cTypeName=this.Context.Ado.DbBind.GetCsharpTypeName(UtilConstants.StringType.Name);
+                var value=UtilMethods.ConvertDataByTypeName(cTypeName, "");
+                if (value != null) 
+                {
+                    var key = "GetNullType_" + tableName + columnName;
+                    return new ReflectionInoCacheService().GetOrCreate(key, () => value.GetType());
+                }
+            }
+            return null;
+        }
     }
 }