php - passing values to sql through check boxes and dropdowns -

how can pass drop down values sql database , check box example if user selects english , maths value inserted in database 1 or else value 0

    <form>         <p id="p1">select year</p>             <select id="year_sel">               <option value="blank"></option>                 <option id="primary" value="primary">primary</option>                      <option value="1">year one</option>                         <option value="2">year two</option>                             <option value="3">year three</option>     </select>     <input type="checkbox" name="math" value="math">math<br>                 <input type="checkbox" name="english" value="english">english<br>                 <input type="checkbox" name="healthscience" value="healthscience">health science<br>  <input class="sub_reg" type="submit" value="register subjects" /> </form> 

this how database looks

first, <select id="year_sel"> needs name attribute post ->

<select id="year_sel" name="year_sel" > 

since using <form> default get, selected value in $_get

$year_sel = $_get['year_sel']; 

if changed

<form method="post"> 

then in $_post

$year_sel = $_post['year_sel'] 

second, checkboxes posted if checked, can use isset() set value using ternary -

$math = isset($_get['math']) ? 1 : 0;  $english = isset($_get['english']) ? 1 : 0; ...[rest of checkboxes]... 

swap $_get/$_post select

$math = isset($_post['math']) ? 1 : 0;  $english = isset($_post['english']) ? 1 : 0;