Update

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,omitempty", db:"updated_at, omitempty"`
 }