How to create custom form and insert data using this form into database in Wordpress?

Question

I am trying to make a custom form and insert into the database but when I click submit nothing happens. Please help me. I did research and changed my code but still same result. I don't know why.

This is the code:

<?php
/*
Template Name: Student
*/
get_header();
?>    
<?php echo "google";?>    
<?php

    if($_POST['Submit'])
        {
         global $wpdb;
         $name=$_POST['aname'];
         $roll=$_POST['aroll'];
         $dept=$_POST['adept'];
              if($wpdb->insert(    
                  'std', array(
                               'name' => $name,
                               'roll' => $roll,
                               'dept' => $dept
                               )
                               ) == false) wp_die('Database insertion failed');
     else 
          echo "<p>Database insertion successful</p>";  
?>
<?php
}
else //else we didnt submit the form, so display the form
{
?>
<form action="" method="post" id="addcourse">
<label> Student Name:<input type="text" 
name="aname" size="30" /></label>
<label> Roll:<input type="text" 
name="aroll" size="30" /></label>
<label> Department:<input type="text" name="adept" size="30" /></label>
<br />
<input type="Submit" id="addcoursesubmit" value="submit" />
</form>
<?php
}

{
}
?>
<?php get_sidebar(); ?>
<?php get_footer(); ?>

Answer 1

I read your whole code there is a small mistake done by you. Try to put name on your input submit.

<input type="Submit" id="addcoursesubmit" value="submit" name="Submit"/>