Woocommerce product in database

Products are located mainly in the following tables:

• wp_posts table with post_type like product (or product_variation),
• wp_postmeta table with post_id as relational index (the product ID).
• wp_wc_product_meta_lookup table with product_id as relational index (the post ID) | Allow fast queries on specific product data (since WooCommerce 3.7)
• wp_wc_order_product_lookuptable with product_id as relational index (the post ID) | Allow fast queries to retrieve products on orders (since WooCommerce 3.7)

Product types, categories, subcategories, tags, attributes and all other custom taxonomies are located in the following tables:

• wp_terms
• wp_termmeta
• wp_term_taxonomy
• wp_term_relationships – column object_id as relational index (the product ID)
• wp_woocommerce_termmeta
• wp_woocommerce_attribute_taxonomies (for product attributes only)
• wp_wc_category_lookup (for product categories hierarchy only since WooCommerce 3.7)

Product types are handled by custom taxonomy product_type with the following default terms:

• simple
• grouped
• variable
• external

Some other product types for Subscriptions and Bookings plugins:

• subscription
• variable-subscription
• booking

Since Woocommerce 3+ a new custom taxonomy named product_visibility handle:

• The product visibility with the terms exclude-from-search and exclude-from-catalog
• The feature products with the term featured
• The stock status with the term outofstock
• The rating system with terms from rated-1 to rated-5

Particular feature: Each product attribute is a custom taxonomy…

References:

• Normal tables: WordPress database description
• Specific tables: Woocommerce database description