diff --git a/Src/Asp.Net/PgSqlTest/Demo/Demo1_Queryable.cs b/Src/Asp.Net/PgSqlTest/Demo/Demo1_Queryable.cs
index 66c0c5028..4475dabba 100644
--- a/Src/Asp.Net/PgSqlTest/Demo/Demo1_Queryable.cs
+++ b/Src/Asp.Net/PgSqlTest/Demo/Demo1_Queryable.cs
@@ -42,6 +42,13 @@ namespace OrmTest
             var getByWhere2 = db.Queryable<Order>().Where(it => it.Id == DateTime.Now.Year).ToList();
             var getByFuns = db.Queryable<Order>().Where(it => SqlFunc.IsNullOrEmpty(it.Name)).ToList();
             var getByFuns2 = db.Queryable<Order>().GroupBy(it => it.Name).Select(it => SqlFunc.AggregateDistinctCount(it.Price)).ToList();
+            var btime = Convert.ToDateTime("2021-1-1");
+            var etime = Convert.ToDateTime("2022-1-12");
+            var test01 = db.Queryable<Order>().Select(it =>  SqlFunc.DateDiff(DateType.Year,btime, etime)).ToList();
+            var test02 = db.Queryable<Order>().Select(it => SqlFunc.DateDiff(DateType.Day, btime, etime)).ToList();
+            var test03 = db.Queryable<Order>().Select(it => SqlFunc.DateDiff(DateType.Month, btime, etime)).ToList();
+            var test04 = db.Queryable<Order>().Select(it => SqlFunc.DateDiff(DateType.Second, DateTime.Now, DateTime.Now.AddMinutes(2))).ToList();
+            Console.WriteLine("#### Examples End ####");
             Console.WriteLine("#### Examples End ####");
         }
 
diff --git a/Src/Asp.Net/SqlSugar/ExpressionsToSql/Common/SugarParameter.cs b/Src/Asp.Net/SqlSugar/ExpressionsToSql/Common/SugarParameter.cs
index 6b3adabb6..4a130ab10 100644
--- a/Src/Asp.Net/SqlSugar/ExpressionsToSql/Common/SugarParameter.cs
+++ b/Src/Asp.Net/SqlSugar/ExpressionsToSql/Common/SugarParameter.cs
@@ -136,6 +136,7 @@ namespace SqlSugar
             else if (type!=null&&type.IsEnum())
             {
                 this.DbType = System.Data.DbType.Int64;
+                this.Value = Convert.ToInt64(Value);
             }
 
         }
diff --git a/Src/Asp.Net/SqlSugar/Realization/PostgreSQL/SqlBuilder/PostgreSQLExpressionContext.cs b/Src/Asp.Net/SqlSugar/Realization/PostgreSQL/SqlBuilder/PostgreSQLExpressionContext.cs
index 9158581bd..98742a969 100644
--- a/Src/Asp.Net/SqlSugar/Realization/PostgreSQL/SqlBuilder/PostgreSQLExpressionContext.cs
+++ b/Src/Asp.Net/SqlSugar/Realization/PostgreSQL/SqlBuilder/PostgreSQLExpressionContext.cs
@@ -133,6 +133,32 @@ namespace SqlSugar
     }
     public class PostgreSQLMethod : DefaultDbMethod, IDbMethods
     {
+        public override string DateDiff(MethodCallExpressionModel model)
+        {
+            var parameter = (DateType)(Enum.Parse(typeof(DateType), model.Args[0].MemberValue.ObjToString()));
+            var begin = model.Args[1].MemberName;
+            var end = model.Args[2].MemberName;
+            switch (parameter)
+            {
+                case DateType.Year:
+                    return $" ( DATE_PART('Year',  {end}   ) - DATE_PART('Year',  {begin}) )";
+                case DateType.Month:
+                    return $" (  ( DATE_PART('Year',  {end}   ) - DATE_PART('Year',  {begin}) ) * 12 + (DATE_PART('month', {end}) - DATE_PART('month', {begin})) )";
+                case DateType.Day:
+                    return $" ( DATE_PART('day', {end} - {begin}) )";
+                case DateType.Hour:
+                    return $" ( ( DATE_PART('day', {end} - {begin}) ) * 24 + DATE_PART('hour', {end} - {begin} ) )";
+                case DateType.Minute:
+                    return $" ( ( ( DATE_PART('day', {end} - {begin}) ) * 24 + DATE_PART('hour', {end} - {begin} ) ) * 60 + DATE_PART('minute', {end} - {begin} ) )";
+                case DateType.Second:
+                    return $" ( ( ( DATE_PART('day', {end} - {begin}) ) * 24 + DATE_PART('hour', {end} - {begin} ) ) * 60 + DATE_PART('minute', {end} - {begin} ) ) * 60 + DATE_PART('minute', {end} - {begin} )";
+                case DateType.Millisecond:
+                    break;
+                default:
+                    break;
+            }
+            throw new Exception(parameter + " datediff no support");
+        }
         public override string IIF(MethodCallExpressionModel model)
         {
             var parameter = model.Args[0];