Knockout binding using key-value pairs

I'm doing knockout with BreezeJs to retrieve and store data from a local database. The problem I am facing here is the key value binding in the menu. What I do is display and select the "Name" property from the select menu and store the corresponding "Id" property into my database.

until now i am trying

var operators = [
{id: 0, name: 'addition'},
{id: 1, name: 'subtraction'},
{id: 2, name: 'division'},
{id: 3, name: 'multiplication'}
   ];

//my html bindings

<select data-bind="options: $root.operators , optionText: 'name', optionvalue: 'Id', value: operator"/>

// Here 'operator' is the colomnName in the database, which I am trying to store as integer format.

But as per my code it shows as

[object object]

How can I fix this so that the "name" property [varchar] is displayed and selected from the select menu and the corresponding "id" property [int] is stored into my database.

// @ TSV

html binding

 <div data-bind="with: jobs">
      <div>
        <label>FirstNumber :</label>
        <input data-bind="value: first_no" />
    </div>

         <div>
        <label>operator :</label>
         <select data-bind="options: $root.operators , optionsText: 'name', optionsValue: 'id', value: $root.operator"/>
    </div>
     <div>
        <label>Second Number:</label>
        <input data-bind="value: second_no" />
    </div><div>
        <label>Result :</label>
        <input data-bind="value: result" />
    </div></div>

//These (results, second_no, operator, first_no) are column names in my database and "jobs" is an observableArray.

Note: I'm using breedJS to fetch and store data from a database, that's why I mention it's tag, although the question above is a knockout and not a breeze.