Get posts from custom tax grouped by terms (MySQL) #WP

Asset.php

// get a list of categories, in this case your custom taxonomy (your_taxonomy_name)
$querystr = "SELECT terms.* FROM $wpdb->term_taxonomy tax LEFT JOIN $wpdb->terms terms ON tax.term_id = terms.term_id WHERE tax.taxonomy = 'retouch_types'";
$categories = $wpdb->get_results($querystr, OBJECT);

// begin a loop through those terms (categories in your custom taxonomy)
foreach( $categories as $category ) {
	echo '<div class="category-header"><h2>'.$category->name.'</h2>'; // print the cat title
	echo '<p class="category-description">'.strip_tags(term_description($category->term_id,'retouch_types')).'</p></div>'; // cat description

	//select posts in this category, and of a specified content type
	$posts = get_posts( array(
		'post_type' => 'retouch',
		'tax_query' => array(
			array(
				'taxonomy' => 'retouch_types',
				'field' => 'slug',
				'terms' => $category->slug
			)
		)
	));
	
	// begin cycle through posts of this category
	foreach($posts as $post) {
		setup_postdata($post); //set up post data for use in the loop (enables the_title(), etc without specifying a post ID)

		the_title();
		the_excerpt();

	} // endforeach;
} //endforeach; ?>