Better support for sql.Scanner

README.md

@@ -27,7 +27,7 @@ type User struct {         // TableName: `users`, gorm will pluralize struct's n
 
 	Email             []Email        // Embedded structs
 	BillingAddress    Address        // Embedded struct
-	BillingAddressId  int64     // Embedded struct BillingAddress's foreign key
+	BillingAddressId  sql.NullInt64  // Embedded struct BillingAddress's foreign key
 	ShippingAddress   Address        // Embedded struct
 	ShippingAddressId int64          // Embedded struct ShippingAddress's foreign key
 }

do.go

@@ -64,7 +64,7 @@ func (s *Do) hasError() bool {
 }
 
 func (s *Do) setModel(value interface{}) *Do {
-	s.model = &Model{data: value, driver: s.driver}
+	s.model = &Model{data: value, driver: s.driver, debug: s.debug}
 	s.value = value
 	return s
 }
@@ -561,8 +561,8 @@ func (s *Do) buildWhereCondition(clause map[string]interface{}) (str string) {
 			}
 			str = strings.Replace(str, "?", strings.Join(temp_marks, ","), 1)
 		default:
-			if scanner, ok := interface{}(arg).(driver.Valuer); ok {
+			if valuer, ok := interface{}(arg).(driver.Valuer); ok {
-				arg, _ = scanner.Value()
+				arg, _ = valuer.Value()
 			}
 			str = strings.Replace(str, "?", s.addToVars(arg), 1)
 		}
@@ -725,6 +725,7 @@ func (s *Do) createTable() *Do {
 		s.tableName(),
 		strings.Join(sqls, ","),
 	)
+
 	s.exec()
 	return s
 }

gorm_test.go

@@ -2,6 +2,7 @@ package gorm
 
 import (
 	"database/sql"
+	"database/sql/driver"
 	"errors"
 	"fmt"
 	_ "github.com/go-sql-driver/mysql"
@@ -1270,36 +1271,58 @@ func TestAutoMigration(t *testing.T) {
 	}
 }
 
+type NullTime struct {
+	Time  time.Time
+	Valid bool
+}
+
+func (nt *NullTime) Scan(value interface{}) error {
+	if value == nil {
+		nt.Valid = false
+		return nil
+	}
+	nt.Time, nt.Valid = value.(time.Time), true
+	return nil
+}
+
+func (nt NullTime) Value() (driver.Value, error) {
+	if !nt.Valid {
+		return nil, nil
+	}
+	return nt.Time, nil
+}
+
 type NullValue struct {
 	Id      int64
 	Name    sql.NullString
 	Age     sql.NullInt64
 	Male    sql.NullBool
 	Height  sql.NullFloat64
+	AddedAt NullTime
 }
 
 func TestSqlNullValue(t *testing.T) {
 	db.DropTable(&NullValue{})
 	db.AutoMigrate(&NullValue{})
 
-	if err := db.Save(&NullValue{Name: sql.NullString{"hello", true}, Age: sql.NullInt64{18, true}, Male: sql.NullBool{true, true}, Height: sql.NullFloat64{100.11, true}}).Error; err != nil {
+	if err := db.Save(&NullValue{Name: sql.NullString{"hello", true}, Age: sql.NullInt64{18, true}, Male: sql.NullBool{true, true}, Height: sql.NullFloat64{100.11, true}, AddedAt: NullTime{time.Now(), true}}).Error; err != nil {
 		t.Errorf("Not error should raise when test null value", err)
 	}
 
 	var nv NullValue
 	db.First(&nv, "name = ?", "hello")
 
-	if nv.Name.String != "hello" || nv.Age.Int64 != 18 || nv.Male.Bool != true || nv.Height.Float64 != 100.11 {
+	if nv.Name.String != "hello" || nv.Age.Int64 != 18 || nv.Male.Bool != true || nv.Height.Float64 != 100.11 || nv.AddedAt.Valid != true {
 		t.Errorf("Should be able to fetch null value")
 	}
 
-	if err := db.Save(&NullValue{Name: sql.NullString{"hello-2", true}, Age: sql.NullInt64{18, false}, Male: sql.NullBool{true, true}, Height: sql.NullFloat64{100.11, true}}).Error; err != nil {
+	if err := db.Save(&NullValue{Name: sql.NullString{"hello-2", true}, Age: sql.NullInt64{18, false}, Male: sql.NullBool{true, true}, Height: sql.NullFloat64{100.11, true}, AddedAt: NullTime{time.Now(), false}}).Error; err != nil {
 		t.Errorf("Not error should raise when test null value", err)
 	}
 
 	var nv2 NullValue
 	db.First(&nv2, "name = ?", "hello-2")
-	if nv2.Name.String != "hello-2" || nv2.Age.Int64 != 0 || nv2.Male.Bool != true || nv2.Height.Float64 != 100.11 {
+	if nv2.Name.String != "hello-2" || nv2.Age.Int64 != 0 || nv2.Male.Bool != true || nv2.Height.Float64 != 100.11 || nv2.AddedAt.Valid != false {
 		t.Errorf("Should be able to fetch null value")
 	}
 }

model.go

@@ -81,7 +81,6 @@ func (m *Model) fields(operation string) (fields []Field) {
 	}
 
 	typ := indirect_value.Type()
-
 	for i := 0; i < typ.NumField(); i++ {
 		p := typ.Field(i)
 		if !p.Anonymous && ast.IsExported(p.Name) {
@@ -137,19 +136,11 @@ func (m *Model) fields(operation string) (fields []Field) {
 						value.Set(reflect.ValueOf(time.Now()))
 					}
 				}
-			}
+				field.SqlType = getSqlType(m.driver, value, 0)
-
+			} else if field.IsPrimaryKey {
-			field.Value = value.Interface()
+				field.SqlType = getPrimaryKeySqlType(m.driver, value, 0)
-
-			if field.IsPrimaryKey {
-				field.SqlType = getPrimaryKeySqlType(m.driver, field.Value, 0)
 			} else {
-				field_value := reflect.ValueOf(field.Value)
+				field_value := reflect.Indirect(value)
-				if field_value.Kind() == reflect.Ptr {
-					if field_value.CanAddr() {
-						field_value = field_value.Elem()
-					}
-				}
 
 				switch field_value.Kind() {
 				case reflect.Slice:
@@ -159,10 +150,11 @@ func (m *Model) fields(operation string) (fields []Field) {
 					}
 					field.afterAssociation = true
 				case reflect.Struct:
-					switch value.Interface().(type) {
+					_, is_scanner := reflect.New(field_value.Type()).Interface().(sql.Scanner)
-					case sql.NullInt64, sql.NullFloat64, sql.NullBool, sql.NullString, time.Time:
+
-						field.SqlType = getSqlType(m.driver, field.Value, 0)
+					if is_scanner {
-					default:
+						field.SqlType = getSqlType(m.driver, value, 0)
+					} else {
 						if indirect_value.FieldByName(p.Name + "Id").IsValid() {
 							field.foreignKey = p.Name + "Id"
 							field.beforeAssociation = true
@@ -174,12 +166,12 @@ func (m *Model) fields(operation string) (fields []Field) {
 							field.afterAssociation = true
 						}
 					}
-				case reflect.Ptr:
-					debug("Errors when handle ptr sub structs")
 				default:
-					field.SqlType = getSqlType(m.driver, field.Value, 0)
+					field.SqlType = getSqlType(m.driver, value, 0)
 				}
 			}
+
+			field.Value = value.Interface()
 			fields = append(fields, field)
 		}
 	}

sql_type.go

@@ -2,11 +2,26 @@ package gorm
 
 import (
 	"database/sql"
+	"database/sql/driver"
 	"fmt"
+	"reflect"
 	"time"
 )
 
+func formatColumnValue(column interface{}) interface{} {
+	if v, ok := column.(reflect.Value); ok {
+		column = v.Interface()
+	}
+
+	if valuer, ok := interface{}(column).(driver.Valuer); ok {
+		column = reflect.New(reflect.ValueOf(valuer).Field(0).Type()).Elem().Interface()
+	}
+	return column
+}
+
 func getPrimaryKeySqlType(adaptor string, column interface{}, size int) string {
+	column = formatColumnValue(column)
+
 	switch adaptor {
 	case "sqlite3":
 		return "INTEGER PRIMARY KEY"
@@ -30,6 +45,8 @@ func getPrimaryKeySqlType(adaptor string, column interface{}, size int) string {
 }
 
 func getSqlType(adaptor string, column interface{}, size int) string {
+	column = formatColumnValue(column)
+
 	switch adaptor {
 	case "sqlite3":
 		switch column.(type) {