How to save checkbox in database?

Question

My doubt is very simple, but I did not find exactly the command I want and I hope you can help me.

I have a vehicle budget page and I want to do a checkbox to select between three models of wheels and I want this to save in the database in the table orçamento as idroda.

I have the bank already created, and the table where I want to save the id of checkbox would be chosen orcamento.

So my goal would be first to save the checkbox in the database.

Just follow my code.

<form action="" method="post" name="checkbox"/>
<div id="ola">
    <label>
        <input type="checkbox" name="ba[]" value="opção 1"/>opção 1<br />
    </label>
    <label>
        <input type="checkbox" name="ba[]" value="opção 2"/>opção 2<br />
    </label>
    <label>
        <input type="checkbox" name="ba[]" value="opção 3"/>opção 3<br />
    </label>
    <input type="hidden" value="enviar" name="acao"/>
    <input type="submit" value="Enviar"/>
</div>
</form>

PHP

if(isset($_POST["ba"])) 
{ 
    echo "você escolheu:<br>"; 
}


if (isset ($_POST['acao']) && $_POST['acao'] == "enviar"){

    if(!empty($_POST['ba'])){
        $campo = $_POST['ba'];
        foreach($campo as $valor){
            echo $valor.'<br/>';
        }
    }
    else{
        echo "Nada marcado";
    }
}