update ignores Custom UpdatedAt time type

go.mod

@@ -25,7 +25,7 @@ require (
 	golang.org/x/crypto v0.14.0 // indirect
 	golang.org/x/mod v0.14.0 // indirect
 	golang.org/x/sys v0.14.0 // indirect
-	golang.org/x/text v0.13.0 // indirect
+	golang.org/x/text v0.14.0 // indirect
 	golang.org/x/tools v0.15.0 // indirect
 	gorm.io/datatypes v1.1.1-0.20230130040222-c43177d3cf8c // indirect
 	gorm.io/hints v1.1.0 // indirect

main_test.go

@@ -11,10 +11,26 @@ import (
 func TestGORM(t *testing.T) {
 	user := User{Name: "jinzhu"}
 
-	DB.Create(&user)
+	if err := DB.Create(&user).Error; err != nil {
+		t.Fatal(err)
+	}
+
+	var st2 User
+	if err := DB.First(&st2, 1).Error; err != nil {
+		t.Fatal(err)
+	}
+
+	if st2.ID != 1 {
+		t.Fatalf("expected ID 1, got %d", st2.ID)
+	}
+
+	st2.Name = "new User"
+	if err := DB.Save(&st2).Error; err != nil {
+		t.Fatal(err)
+	}
 
-	var result User
-	if err := DB.First(&result, user.ID).Error; err != nil {
-		t.Errorf("Failed, got error: %v", err)
+	var st3 User
+	if err := DB.First(&st3, 1).Error; err != nil {
+		t.Fatal(err)
 	}
 }

models.go

@@ -2,31 +2,23 @@ package main
 
 import (
 	"database/sql"
+	"database/sql/driver"
+	"fmt"
 	"time"
 
 	"gorm.io/gorm"
+	"gorm.io/gorm/schema"
 )
 
 // User has one `Account` (has one), many `Pets` (has many) and `Toys` (has many - polymorphic)
 // He works in a Company (belongs to), he has a Manager (belongs to - single-table), and also managed a Team (has many - single-table)
 // He speaks many languages (many to many) and has many friends (many to many - single-table)
 // His pet also has one Toy (has one - polymorphic)
 type User struct {
-	gorm.Model
+	ID        uint `gorm:"primarykey"`
 	Name      string
-	Age       uint
-	Birthday  *time.Time
-	Account   Account
-	Pets      []*Pet
-	Toys      []Toy `gorm:"polymorphic:Owner"`
-	CompanyID *int
-	Company   Company
-	ManagerID *uint
-	Manager   *User
-	Team      []User     `gorm:"foreignkey:ManagerID"`
-	Languages []Language `gorm:"many2many:UserSpeak"`
-	Friends   []*User    `gorm:"many2many:user_friends"`
-	Active    bool
+	CreatedAt Time `gorm:"not null"`
+	UpdatedAt Time `gorm:"not null"`
 }
 
 type Account struct {
@@ -58,3 +50,68 @@ type Language struct {
 	Code string `gorm:"primarykey"`
 	Name string
 }
+
+type Time struct {
+	date time.Time
+}
+
+func NewTime(year, month, day, hour, min, sec int) Time {
+	return Time{
+		date: time.Date(year, time.Month(month), day, hour, min, sec, 0, time.UTC),
+	}
+}
+
+// GormDataType returns gorm common data type. This type is used for the field's column type.
+func (Time) GormDataType() string {
+	return "time"
+}
+
+// GormDBDataType returns gorm DB data type based on the current using database.
+func (Time) GormDBDataType(db *gorm.DB, field *schema.Field) string {
+	switch db.Dialector.Name() {
+	case "mysql":
+		return "TIME"
+	case "postgres":
+		return "TIME"
+	case "sqlserver":
+		return "TIME"
+	case "sqlite":
+		return "TEXT"
+	default:
+		return ""
+	}
+}
+
+// Scan implements sql.Scanner interface and scans value into Time,
+func (t *Time) Scan(src interface{}) error {
+	switch v := src.(type) {
+	case []byte:
+		return t.setFromString(string(v))
+	case string:
+		return t.setFromString(v)
+	case time.Time:
+		t.setFromTime(v)
+	default:
+		return fmt.Errorf("failed to scan value: %v", v)
+	}
+
+	return nil
+}
+
+func (t *Time) setFromString(str string) error {
+	time, err := time.Parse(time.DateTime, str)
+	if err != nil {
+		return err
+	}
+	t.date = time
+	return nil
+}
+
+func (t *Time) setFromTime(src time.Time) {
+	*t = NewTime(src.Year(), int(src.Month()), src.Day(), src.Hour(), src.Minute(), src.Second())
+}
+
+// Value implements driver.Valuer interface and returns string format of Time.
+func (t Time) Value() (driver.Value, error) {
+	return t.date.Format(time.DateTime), nil
+}