Update demo

Src/Asp.Net/OracleTest/Demo/Demo1_Queryable.cs

@@ -132,7 +132,8 @@ namespace OrmTest
                      datetime=it.CreateTime
                 })
                .ToList();
-
+            var list3 = db.Queryable<Order>().Where(it => it.CreateTime.Date == SqlFunc.Oracle_ToDate("2021-1-21", "yyyy-MM-dd")).ToList();
+            var list4 = db.Queryable<Order>().Select(it => SqlFunc.Oracle_ToChar(DateTime.Now, "yyyy-MM-dd")).ToList();
             Console.WriteLine("#### SqlFunc  End ####");
         }
 

Src/Asp.Net/SqlServerTest/Demo/Demo1_Queryable.cs

@@ -130,6 +130,8 @@ namespace OrmTest
               .Any()
             ).ToList();
 
+            var list3=db.Queryable<Order>().Select(it => SqlFunc.SqlServer_DateDiff("day", DateTime.Now.AddDays(-1), DateTime.Now)).ToList();
+
             Console.WriteLine("#### Subquery End ####");
         }
 

Src/Asp.Net/SqlSugar/ExpressionsToSql/DbMethods/SqlFunc.cs

@@ -140,8 +140,8 @@ namespace SqlSugar
         public static int CharIndex(string findChar,string searchValue) { throw new NotSupportedException("Can only be used in expressions"); }
         public static int BitwiseAnd(int left, int right) { throw new NotSupportedException("Can only be used in expressions"); }
         public static int BitwiseInclusiveOR(int left, int right) { throw new NotSupportedException("Can only be used in expressions"); }
-        public static DateTime Oracle_ToDate(object date,string format) { throw new NotSupportedException("Can only be used in expressions"); }
-        public static string Oracle_ToChar(object date, string format) { throw new NotSupportedException("Can only be used in expressions"); }
+        public static DateTime Oracle_ToDate(string date,string format) { throw new NotSupportedException("Can only be used in expressions"); }
+        public static string Oracle_ToChar(DateTime date, string format) { throw new NotSupportedException("Can only be used in expressions"); }
         public static int SqlServer_DateDiff(string dateType,DateTime date1,DateTime date2) { throw new NotSupportedException("Can only be used in expressions"); }
     }
 }