Insert data in database using form

Hello WordPress admin,

I have created the form and insert data into database, after submit the “alert box” it says unable to save. this is my code in function.php

if (isset($_POST['submitbtn'])) {
		$data = array(
			'title' => $_POST['title'],
			'author' => $_POST['author'],
		);
		$table_name ='mybook';

		$result = $wpdb->insert($table_name, $data, $format=null);

		if ($result==1)
		 {
			echo "<script>alert('Book Saved');</script>";
		}else{
			echo "<script>alert('Unable to Save');</script>";
		}

	}

and this my code to my frontpage.php

<form  method="post" >
              <div class="form-group">
                <input id="title" type="text" name="title" placeholder="Book Title" class="form-group input-sm">
              </div>  

              <div class="form-group">
                <input id="author" type="text" name="author" placeholder="author" class="form-group input-sm">
              </div>
              <div class="row justify-content-center">
                <div class="col-xs-4 col-sm-4 col-md-4">
                  <input type="submit" value="Submit" class="btn btn-info btn-block" name="submitbtn">
                </div>
              </div>
           </form>

• This topic was modified 5 years, 9 months ago by andz89.
• This topic was modified 5 years, 9 months ago by Jan Dembowski. Reason: Formatting