models update

model/catalog.go

@@ -8,5 +8,5 @@ type ProductModel struct {
 	Name      string           `db:"name"`
 	Price     float64          `db:"price"`
 	CreatedAt pgtype.Timestamp `db:"created_at"`
-	UpdatedAt pgtype.Timestamp `db:"updated_at"`
+	UpdatedAt pgtype.Timestamp `db:"updated_at,omitempty"`
 }