Useful Wordpress SQL Queries - Use at own risk.

delete_all_cats_woocommerce.sql

DELETE a,c FROM wp_terms AS a
LEFT JOIN wp_term_taxonomy AS c ON a.term_id = c.term_id
LEFT JOIN wp_term_relationships AS b ON b.term_taxonomy_id = c.term_taxonomy_id
WHERE c.taxonomy = 'product_tag';
DELETE a,c FROM wp_terms AS a
LEFT JOIN wp_term_taxonomy AS c ON a.term_id = c.term_id
LEFT JOIN wp_term_relationships AS b ON b.term_taxonomy_id = c.term_taxonomy_id
WHERE c.taxonomy = 'product_cat';

delete_all_orders_woocommerce.sql

DELETE FROM wp_woocommerce_order_itemmeta;
DELETE FROM wp_woocommerce_order_items;
DELETE FROM wp_comments WHERE comment_type = 'order_note';
DELETE FROM wp_postmeta WHERE post_id IN ( SELECT ID FROM wp_posts WHERE post_type = 'shop_order' );
DELETE FROM wp_posts WHERE post_type = 'shop_order';

delete_all_products_woocommerce.sql

DELETE relations., taxes., terms.*
FROM wp_term_relationships AS relations
INNER JOIN wp_term_taxonomy AS taxes
ON relations.term_taxonomy_id=taxes.term_taxonomy_id
INNER JOIN wp_terms AS terms
ON taxes.term_id=terms.term_id
WHERE object_id IN (SELECT ID FROM wp_posts WHERE post_type='product');
DELETE FROM wp_postmeta WHERE post_id IN (SELECT ID FROM wp_posts WHERE post_type = 'product');
DELETE FROM wp_posts WHERE post_type = 'product';

migrate.sql

UPDATE wp_options SET option_value = replace(option_value, 'URL-1', 'URL-2') WHERE option_name = 'home' OR option_name = 'siteurl';
UPDATE wp_posts SET guid = replace(guid, 'URL-1','URL-2');
UPDATE wp_posts SET post_content = replace(post_content, 'URL-1', 'URL-2');
UPDATE wp_posts SET post_excerpt = replace(post_excerpt, 'URL-1', 'URL-2');
UPDATE wp_postmeta SET meta_value = replace(meta_value, 'URL-1', 'URL-2');