Truncate the test data in Magento

This script will start you over, remember to backup first!

SET FOREIGN_KEY_CHECKS=0;

TRUNCATE `sales_order`;
TRUNCATE `sales_order_datetime`;
TRUNCATE `sales_order_decimal`;
TRUNCATE `sales_order_entity`;
TRUNCATE `sales_order_entity_datetime`;
TRUNCATE `sales_order_entity_decimal`;
TRUNCATE `sales_order_entity_int`;
TRUNCATE `sales_order_entity_text`;
TRUNCATE `sales_order_entity_varchar`;
TRUNCATE `sales_order_int`;
TRUNCATE `sales_order_text`;
TRUNCATE `sales_order_varchar`;
TRUNCATE `sales_flat_quote`;
TRUNCATE `sales_flat_quote_address`;
TRUNCATE `sales_flat_quote_address_item`;
TRUNCATE `sales_flat_quote_item`;
TRUNCATE `sales_flat_quote_item_option`;
TRUNCATE `sales_flat_order_item`;
TRUNCATE `sendfriend_log`;
TRUNCATE `tag`;
TRUNCATE `tag_relation`;
TRUNCATE `tag_summary`;
TRUNCATE `wishlist`;
TRUNCATE `log_quote`;
TRUNCATE `report_event`;

ALTER TABLE `sales_order` AUTO_INCREMENT=1;
ALTER TABLE `sales_order_datetime` AUTO_INCREMENT=1;
ALTER TABLE `sales_order_decimal` AUTO_INCREMENT=1;
ALTER TABLE `sales_order_entity` AUTO_INCREMENT=1;
ALTER TABLE `sales_order_entity_datetime` AUTO_INCREMENT=1;
ALTER TABLE `sales_order_entity_decimal` AUTO_INCREMENT=1;
ALTER TABLE `sales_order_entity_int` AUTO_INCREMENT=1;
ALTER TABLE `sales_order_entity_text` AUTO_INCREMENT=1;
ALTER TABLE `sales_order_entity_varchar` AUTO_INCREMENT=1;
ALTER TABLE `sales_order_int` AUTO_INCREMENT=1;
ALTER TABLE `sales_order_text` AUTO_INCREMENT=1;
ALTER TABLE `sales_order_varchar` AUTO_INCREMENT=1;
ALTER TABLE `sales_flat_quote` AUTO_INCREMENT=1;
ALTER TABLE `sales_flat_quote_address` AUTO_INCREMENT=1;
ALTER TABLE `sales_flat_quote_address_item` AUTO_INCREMENT=1;
ALTER TABLE `sales_flat_quote_item` AUTO_INCREMENT=1;
ALTER TABLE `sales_flat_quote_item_option` AUTO_INCREMENT=1;
ALTER TABLE `sales_flat_order_item` AUTO_INCREMENT=1;
ALTER TABLE `sendfriend_log` AUTO_INCREMENT=1;
ALTER TABLE `tag` AUTO_INCREMENT=1;
ALTER TABLE `tag_relation` AUTO_INCREMENT=1;
ALTER TABLE `tag_summary` AUTO_INCREMENT=1;
ALTER TABLE `wishlist` AUTO_INCREMENT=1;
ALTER TABLE `log_quote` AUTO_INCREMENT=1;
ALTER TABLE `report_event` AUTO_INCREMENT=1;

-- reset customers
TRUNCATE `customer_address_entity`;
TRUNCATE `customer_address_entity_datetime`;
TRUNCATE `customer_address_entity_decimal`;
TRUNCATE `customer_address_entity_int`;
TRUNCATE `customer_address_entity_text`;
TRUNCATE `customer_address_entity_varchar`;
TRUNCATE `customer_entity`;
TRUNCATE `customer_entity_datetime`;
TRUNCATE `customer_entity_decimal`;
TRUNCATE `customer_entity_int`;
TRUNCATE `customer_entity_text`;
TRUNCATE `customer_entity_varchar`;
TRUNCATE `log_customer`;
TRUNCATE `log_visitor`;
TRUNCATE `log_visitor_info`;

ALTER TABLE `customer_address_entity` AUTO_INCREMENT=1;
ALTER TABLE `customer_address_entity_datetime` AUTO_INCREMENT=1;
ALTER TABLE `customer_address_entity_decimal` AUTO_INCREMENT=1;
ALTER TABLE `customer_address_entity_int` AUTO_INCREMENT=1;
ALTER TABLE `customer_address_entity_text` AUTO_INCREMENT=1;
ALTER TABLE `customer_address_entity_varchar` AUTO_INCREMENT=1;
ALTER TABLE `customer_entity` AUTO_INCREMENT=1;
ALTER TABLE `customer_entity_datetime` AUTO_INCREMENT=1;
ALTER TABLE `customer_entity_decimal` AUTO_INCREMENT=1;
ALTER TABLE `customer_entity_int` AUTO_INCREMENT=1;
ALTER TABLE `customer_entity_text` AUTO_INCREMENT=1;
ALTER TABLE `customer_entity_varchar` AUTO_INCREMENT=1;
ALTER TABLE `log_customer` AUTO_INCREMENT=1;
ALTER TABLE `log_visitor` AUTO_INCREMENT=1;
ALTER TABLE `log_visitor_info` AUTO_INCREMENT=1;

-- Reset all ID counters
TRUNCATE `eav_entity_store`;
ALTER TABLE `eav_entity_store` AUTO_INCREMENT=1;

SET FOREIGN_KEY_CHECKS=1;