diff --git a/do.go b/do.go
index 4548bd93..05c2a681 100644
--- a/do.go
+++ b/do.go
@@ -2,6 +2,7 @@ package gorm
 
 import (
 	"database/sql"
+	"database/sql/driver"
 	"errors"
 	"fmt"
 	"reflect"
@@ -560,13 +561,10 @@ func (s *Do) buildWhereCondition(clause map[string]interface{}) (str string) {
 			}
 			str = strings.Replace(str, "?", strings.Join(temp_marks, ","), 1)
 		default:
-			switch arg.(type) {
-			case sql.NullInt64, sql.NullFloat64, sql.NullBool, sql.NullString:
-				value := reflect.ValueOf(arg).Field(0).Interface()
-				str = strings.Replace(str, "?", s.addToVars(value), 1)
-			default:
-				str = strings.Replace(str, "?", s.addToVars(arg), 1)
+			if scanner, ok := interface{}(arg).(driver.Valuer); ok {
+				arg, _ = scanner.Value()
 			}
+			str = strings.Replace(str, "?", s.addToVars(arg), 1)
 		}
 	}
 	return
@@ -624,13 +622,10 @@ func (s *Do) buildNotCondition(clause map[string]interface{}) (str string) {
 			}
 			str = strings.Replace(str, "?", strings.Join(temp_marks, ","), 1)
 		default:
-			switch arg.(type) {
-			case sql.NullInt64, sql.NullFloat64, sql.NullBool, sql.NullString:
-				value := reflect.ValueOf(arg).Field(0).Interface()
-				str = strings.Replace(not_equal_sql, "?", s.addToVars(value), 1)
-			default:
-				str = strings.Replace(not_equal_sql, "?", s.addToVars(arg), 1)
+			if scanner, ok := interface{}(arg).(driver.Valuer); ok {
+				arg, _ = scanner.Value()
 			}
+			str = strings.Replace(not_equal_sql, "?", s.addToVars(arg), 1)
 		}
 	}
 	return
diff --git a/model.go b/model.go
index 90a9d591..1ad17e26 100644
--- a/model.go
+++ b/model.go
@@ -14,6 +14,7 @@ import (
 type Model struct {
 	data          interface{}
 	driver        string
+	debug         bool
 	_cache_fields map[string][]Field
 }
 
@@ -106,11 +107,13 @@ func (m *Model) fields(operation string) (fields []Field) {
 				if is_time {
 					field.IsBlank = time_value.IsZero()
 				} else {
-					switch value.Interface().(type) {
-					case sql.NullInt64, sql.NullFloat64, sql.NullBool, sql.NullString:
+					_, is_scanner := reflect.New(value.Type()).Interface().(sql.Scanner)
+
+					if is_scanner {
 						field.IsBlank = !value.FieldByName("Valid").Interface().(bool)
-					default:
+					} else {
 						m := &Model{data: value.Interface(), driver: m.driver}
+
 						fields := m.columnsHasValue("other")
 						if len(fields) == 0 {
 							field.IsBlank = true
@@ -370,25 +373,14 @@ func setFieldValue(field reflect.Value, value interface{}) bool {
 			}
 			field.SetInt(reflect.ValueOf(value).Int())
 		default:
-			field_type := field.Type()
-			if field_type == reflect.TypeOf(value) {
-				field.Set(reflect.ValueOf(value))
-			} else if value == nil {
-				field.Set(reflect.Zero(field.Type()))
-			} else if field_type == reflect.TypeOf(sql.NullBool{}) {
-				field.Set(reflect.ValueOf(sql.NullBool{value.(bool), true}))
-			} else if field_type == reflect.TypeOf(sql.NullFloat64{}) {
-				field.Set(reflect.ValueOf(sql.NullFloat64{value.(float64), true}))
-			} else if field_type == reflect.TypeOf(sql.NullInt64{}) {
-				field.Set(reflect.ValueOf(sql.NullInt64{value.(int64), true}))
-			} else if field_type == reflect.TypeOf(sql.NullString{}) {
-				field.Set(reflect.ValueOf(sql.NullString{value.(string), true}))
+			if scanner, ok := field.Addr().Interface().(sql.Scanner); ok {
+				scanner.Scan(value)
 			} else {
 				field.Set(reflect.ValueOf(value))
 			}
 		}
 		return true
-	} else {
-		return false
 	}
+
+	return false
 }
diff --git a/utils.go b/utils.go
index 6277bc40..0848ec0b 100644
--- a/utils.go
+++ b/utils.go
@@ -2,8 +2,8 @@ package gorm
 
 import (
 	"bytes"
-	"fmt"
 
+	"fmt"
 	"strings"
 )