i have code like :

```
data = await photo.findOne({
    where : {id}
})

```

that return data

```
{
     "a" : 2,
     "b" : 5
}

```

i want to manipulate the data like insert some field

so i add properties :

```
data.c = data.a * data.b

```

i check in console.log the data added

```
{
     "a" : 2,
     "b" : 5,
     "c" " 10
}

```

but when i return to json

```
 return res.status(200).json({message: "success", data })

```

the data still like first
 {
 "a" : 2,
 "b" : 5
 }