Need Idea foreach

Hi CI Team,
How to foreach data like below,

Database :

Code:

ID | viewed | code
1 | 15 | US
2 | 20 | SG
3 | 10 | US
4 | 30 | SG
5 | 30 | SG
6 | 55 | MY

How to get output like below,

Code:

var gdpData = {"US": 25,

"SG": 80,

"MY": 55,
};

Thanks