store multi select widget values to database

How to store multi select widget values to database?

here is my code…

<label>To</label><br/>

<?php

$data = ArrayHelper::map(Form::find()->all(), ‘name’, ‘email’);

echo MultiSelect::widget([

‘id’=>“to”,

“options” => [‘multiple’=>“multiple”],

‘data’ =>$data,

‘value’ => [ ],

‘name’ => ‘to_email’,

"clientOptions" =>

[

"includeSelectAllOption" => true,

‘numberDisplayed’ => 1

],

]);

i want select multiple emails and store them into database…

below attachment contain snapshot of view page.