Pour remettre à zéro toutes les commandes passées en test sur votre serveur de développement avant de passer en serveur de production (ou pré-prod) :

Exécuter la commande SQL suivante :

Attention, cela supprime aussi les clients de test !

Magento >= 1.4.*.* :

TRUNCATE  `customer_address_entity` ;
ALTER TABLE customer_address_entity AUTO_INCREMENT=0;
TRUNCATE  `customer_address_entity_datetime` ;
ALTER TABLE customer_address_entity_datetime AUTO_INCREMENT=0;
TRUNCATE  `customer_address_entity_decimal` ;
ALTER TABLE customer_address_entity_decimal AUTO_INCREMENT=0;
TRUNCATE  `customer_address_entity_int` ;
ALTER TABLE customer_address_entity_int AUTO_INCREMENT=0;
TRUNCATE  `customer_address_entity_text` ;
ALTER TABLE customer_address_entity_text AUTO_INCREMENT=0;
TRUNCATE  `customer_address_entity_varchar` ;
ALTER TABLE customer_address_entity_varchar AUTO_INCREMENT=0;
TRUNCATE  `customer_entity` ;
ALTER TABLE customer_entity AUTO_INCREMENT=0;
TRUNCATE  `customer_entity_datetime` ;
ALTER TABLE customer_entity_datetime AUTO_INCREMENT=0;
TRUNCATE  `customer_entity_decimal` ;
ALTER TABLE customer_entity_decimal AUTO_INCREMENT=0;
TRUNCATE  `customer_entity_int` ;
ALTER TABLE customer_entity_int AUTO_INCREMENT=0;
TRUNCATE  `customer_entity_text` ;
ALTER TABLE customer_entity_text AUTO_INCREMENT=0;
TRUNCATE  `customer_entity_varchar` ;
ALTER TABLE customer_entity_varchar AUTO_INCREMENT=0;
TRUNCATE  `eav_entity_store` ;
ALTER TABLE eav_entity_store AUTO_INCREMENT=0;
TRUNCATE  `sales_flat_order` ;
ALTER TABLE sales_flat_order AUTO_INCREMENT=0;
TRUNCATE  `sales_flat_order_address` ;
ALTER TABLE sales_flat_order_address AUTO_INCREMENT=0;
TRUNCATE  `sales_flat_order_grid` ;
ALTER TABLE sales_flat_order_grid AUTO_INCREMENT=0;
TRUNCATE  `sales_flat_order_item` ;
ALTER TABLE sales_flat_order_item AUTO_INCREMENT=0;
TRUNCATE  `sales_flat_order_payment` ;
ALTER TABLE sales_flat_order_payment AUTO_INCREMENT=0;
TRUNCATE  `sales_flat_order_status_history` ;
ALTER TABLE sales_flat_order_status_history AUTO_INCREMENT=0;
TRUNCATE  `sales_flat_quote` ;
ALTER TABLE sales_flat_quote AUTO_INCREMENT=0;
TRUNCATE  `sales_flat_quote_address` ;
ALTER TABLE sales_flat_quote_address AUTO_INCREMENT=0;
TRUNCATE  `sales_flat_quote_address_item` ;
ALTER TABLE sales_flat_quote_address_item AUTO_INCREMENT=0;
TRUNCATE  `sales_flat_quote_item` ;
ALTER TABLE sales_flat_quote_item AUTO_INCREMENT=0;
TRUNCATE  `sales_flat_quote_item_option` ;
ALTER TABLE sales_flat_quote_item_option AUTO_INCREMENT=0;
TRUNCATE  `sales_flat_quote_payment` ;
ALTER TABLE sales_flat_quote_payment AUTO_INCREMENT=0;
TRUNCATE  `sales_flat_quote_shipping_rate` ;
ALTER TABLE sales_flat_quote_shipping_rate AUTO_INCREMENT=0;
TRUNCATE  `sales_order_tax` ;
ALTER TABLE sales_order_tax AUTO_INCREMENT=0;

Source

Magento < 1.4 :

DELETE FROM sales_flat_order_item;
DELETE FROM sales_flat_quote;
DELETE FROM sales_flat_quote_address;
DELETE FROM sales_flat_quote_address_item;
DELETE FROM sales_flat_quote_item;
DELETE FROM sales_flat_quote_item_option;
DELETE FROM sales_flat_quote_payment;
DELETE FROM sales_flat_quote_shipping_rate;
DELETE FROM sales_order;
DELETE FROM sales_order_datetime;
DELETE FROM sales_order_decimal;
DELETE FROM sales_order_entity;
DELETE FROM sales_order_entity_datetime;
DELETE FROM sales_order_entity_decimal;
DELETE FROM sales_order_entity_int;
DELETE FROM sales_order_entity_text;
DELETE FROM sales_order_entity_varchar;
DELETE FROM sales_order_int;
DELETE FROM sales_order_tax;
DELETE FROM sales_order_text;
DELETE FROM sales_order_varchar;
DELETE FROM eav_entity_store;

Note : Article à part pour la suppression d’une commande spécifique dans Magento