Let’s see some of the tables that WooCommerce uses in it’s database.
This is the table that your order details for each user are stored.
Each order is given a unique order ID. So, the rows in the table that have the same ID, all refer to the same order.
This field can take 2 values, line_item and shipping. Thev value line_item indicates that this order row refers to a product in the order while the value shipping indicates that this order row refers to the shipping method of the order.
If order_item_type has the value of line_item, then this field takes the name of the product.
If order_item_type has the value of line_item, then this field takes the name of the shipping method (eg. Free Shipping).
This is the table that the meta data for each one of your rows in the wp_woocommerce_order_items are stored.