Update

catalog/dto/product.go

@@ -14,7 +14,7 @@ type GetProductResponseDTO struct {
 	Slug      string     `json:"slug"`
 	Price     float64    `json:"price"`
 	CreatedAt time.Time  `json:"created_at"`
-	UpdatedAt time.Time `json:"updated_at,omitempty"`
+	UpdatedAt *time.Time `json:"updated_at"`
 }
 
 type GetProductListRequestDTO struct {

catalog/entity/product.go

@@ -8,5 +8,5 @@ type Product struct {
 	Name      string     `json:"name", db:"name"`
 	Price     float64    `json:"price", db:"price"`
 	CreatedAt time.Time  `json:"created_at", db:"created_at"`
-	UpdatedAt time.Time `json:"updated_at",db:"updated_at,omitempty"`
+	UpdatedAt *time.Time `json:"updated_at", db:"updated_at, omitempty"`
 }

catalog/model/product.go

@@ -9,5 +9,5 @@ type Product struct {
 	Slug      string     `db:"slug"`
 	Price     float64    `db:"price"`
 	CreatedAt time.Time  `db:"created_at"`
-	UpdatedAt time.Time `db:"updated_at,omitempty"`
+	UpdatedAt *time.Time `db:"updated_at"`
 }

identity/entity/user.go

@@ -8,7 +8,7 @@ type User struct {
 	Username  string     `db:"username" json:"username"`
 	Password  string     `db:"password" json:"password"`
 	CreatedAt time.Time  `db:"created_at" json:"created_at"`
-	ModifiedAt time.Time `db:"modified_at" json:"modified_at"` // FIXME: zero-value issue
+	UpdatedAt *time.Time `db:"updated_at,omitempty" json:"updated_at,omitempty"` // FIXME: zero-value issue
 }
 
 // var TestUser = &User{