is there a way to add column in backend of products for sales count

Hi, @s10dulkar!

Yes, the following code should add a “Total sales” column to the products:

add_filter( 'manage_edit-product_columns', 'misha_total_sales_1', 20 );

add_action( 'manage_posts_custom_column', 'misha_total_sales_2' );

add_filter('manage_edit-product_sortable_columns', 'misha_total_sales_3');

add_action( 'pre_get_posts', 'misha_total_sales_4' );
 
function misha_total_sales_1( $col_th ) {
 
	return wp_parse_args( array( 'total_sales' => 'Total Sales' ), $col_th );
}
 
function misha_total_sales_2( $column_id ) {
 
	if( $column_id  == 'total_sales' )
		echo get_post_meta( get_the_ID(), 'total_sales', true );
}
 
function misha_total_sales_3( $a ){
	return wp_parse_args( array( 'total_sales' => 'by_total_sales' ), $a );
}
 
function misha_total_sales_4( $query ) {
 
	if( !is_admin() || empty( $_GET['orderby']) || empty( $_GET['order'] ) )
		return;
 
	if( $_GET['orderby'] == 'by_total_sales' ) {
		$query->set('meta_key', 'total_sales' );
		$query->set('orderby', 'meta_value_num');
		$query->set('order', $_GET['order'] );
	}
 
	return $query;
 
}

Also see: http://rynaldostoltz.com/how-to-add-custom-code-to-your-woocommerce-wordpress-site-the-right-way/

Cheers!

@s10dulkar
Did you use the code snippets plugin or functions.php?

functions.php of your main theme is not a good place because any edits will be overwritten by theme updates.

functions.php in a child theme would be good.

If there is some other code in functions.php above this new code, does it end with php enabled? If it ends with ?>, php is switched off before it gets to the additional lines, so re activate it with the php opening tag <?php.

Check the syntax in the whole of functions.php by copying and pasting its code in this validation service:
http://phpcodechecker.com/

In the event of it still not working, please copy and paste functions.php here:
https://pastebin.com/
(free service) and paste just the link in this thread so someone can take a look at it.