devices
id | name
1  | iphone
2  | samsung

categories
id | name
1  | Locations
2  | Statuses
3  | Protocols
4  | Accounts
5  | Phone_Numbers


attributes
id | category_id | name | type
1  | 1 | lat  | text
2  | 2 | name | select
3  | 3 | name | select
4  | 4 | name | select
5  | 4 | vendor_id | text
6  | 4 | account_number | text
7  | 4 | data_limit_gig | text
8  | 5 | phone_number | text
9  | 1 | lng  | text


options
id | attribute_id | value
1  | 1 | In Office
2  | 1 | Qwe
3  | 2 | Active



devices_values
id | device_id | attribute_id | option_id | value | start_date | end_date | active | created | modified
1  | 1 | 1 | null | 23.02  | 2017-04-02 12:00:00 | 2017-04-12 13:00:00 | 1 | 2017-04-02 12:00:00 | 2017-04-12 13:00:00
2  | 1 | null | 1 | Active |
3  | 2 | 8 | null | 666666666
itd