Delete all customers and orders from Magento 1*

delete_customers_and_orders_from_magento.sql

--
-- This query delelets all customers and orders from your 
-- Magento 1.* install. Handy, if you have a bloated 
-- Magento database and you need to do a bit 
-- of cleaning up for use on a local machine.
--
-- Replace PREFIX_ with your current Magento table prefix.
--
-- USE AT OWN RISK. ALWAY BACKUP YOUR DATABASE FIRST.
--

-- -----------------------------------------
-- delete all customers and customer logs --
-- -----------------------------------------

SET FOREIGN_KEY_CHECKS = 0;

TRUNCATE PREFIX_customer_address_entity;
TRUNCATE PREFIX_customer_address_entity_datetime;
TRUNCATE PREFIX_customer_address_entity_decimal;
TRUNCATE PREFIX_customer_address_entity_int;
TRUNCATE PREFIX_customer_address_entity_text;
TRUNCATE PREFIX_customer_address_entity_varchar;
TRUNCATE PREFIX_customer_entity;
TRUNCATE PREFIX_customer_entity_datetime;
TRUNCATE PREFIX_customer_entity_decimal;
TRUNCATE PREFIX_customer_entity_int;
TRUNCATE PREFIX_customer_entity_text;
TRUNCATE PREFIX_customer_entity_varchar;
TRUNCATE PREFIX_log_customer;
TRUNCATE PREFIX_log_visitor;
TRUNCATE PREFIX_log_visitor_info;

ALTER TABLE PREFIX_customer_address_entity AUTO_INCREMENT=1;
ALTER TABLE PREFIX_customer_address_entity_datetime AUTO_INCREMENT=1;
ALTER TABLE PREFIX_customer_address_entity_decimal AUTO_INCREMENT=1;
ALTER TABLE PREFIX_customer_address_entity_int AUTO_INCREMENT=1;
ALTER TABLE PREFIX_customer_address_entity_text AUTO_INCREMENT=1;
ALTER TABLE PREFIX_customer_address_entity_varchar AUTO_INCREMENT=1;
ALTER TABLE PREFIX_customer_entity AUTO_INCREMENT=1;
ALTER TABLE PREFIX_customer_entity_datetime AUTO_INCREMENT=1;
ALTER TABLE PREFIX_customer_entity_decimal AUTO_INCREMENT=1;
ALTER TABLE PREFIX_customer_entity_int AUTO_INCREMENT=1;
ALTER TABLE PREFIX_customer_entity_text AUTO_INCREMENT=1;
ALTER TABLE PREFIX_customer_entity_varchar AUTO_INCREMENT=1;
ALTER TABLE PREFIX_log_customer AUTO_INCREMENT=1;
ALTER TABLE PREFIX_log_visitor AUTO_INCREMENT=1;
ALTER TABLE PREFIX_log_visitor_info AUTO_INCREMENT=1;

SET FOREIGN_KEY_CHECKS = 1;

-- --------------------
-- delete all orders --
-- --------------------

SET FOREIGN_KEY_CHECKS = 0;

TRUNCATE PREFIX_sales_flat_creditmemo; 
TRUNCATE PREFIX_sales_flat_creditmemo_comment; 
TRUNCATE PREFIX_sales_flat_creditmemo_grid; 
TRUNCATE PREFIX_sales_flat_creditmemo_item; 
TRUNCATE PREFIX_sales_flat_invoice; 
TRUNCATE PREFIX_sales_flat_invoice_comment; 
TRUNCATE PREFIX_sales_flat_invoice_grid; 
TRUNCATE PREFIX_sales_flat_invoice_item; 
TRUNCATE PREFIX_sales_flat_order; 
TRUNCATE PREFIX_sales_flat_order_address; 
TRUNCATE PREFIX_sales_flat_order_grid; 
TRUNCATE PREFIX_sales_flat_order_item; 
TRUNCATE PREFIX_sales_flat_order_payment; 
TRUNCATE PREFIX_sales_flat_order_status_history; 
TRUNCATE PREFIX_sales_flat_quote; 
TRUNCATE PREFIX_sales_flat_quote_address; 
TRUNCATE PREFIX_sales_flat_quote_address_item; 
TRUNCATE PREFIX_sales_flat_quote_item; 
TRUNCATE PREFIX_sales_flat_quote_item_option; 
TRUNCATE PREFIX_sales_flat_quote_payment; 
TRUNCATE PREFIX_sales_flat_quote_shipping_rate; 
TRUNCATE PREFIX_sales_flat_shipment; 
TRUNCATE PREFIX_sales_flat_shipment_comment; 
TRUNCATE PREFIX_sales_flat_shipment_grid; 
TRUNCATE PREFIX_sales_flat_shipment_item; 
TRUNCATE PREFIX_sales_flat_shipment_track; 
TRUNCATE PREFIX_sales_invoiced_aggregated; 
TRUNCATE PREFIX_sales_invoiced_aggregated_order; 
TRUNCATE PREFIX_sales_payment_transaction;
TRUNCATE PREFIX_sales_order_aggregated_created; 
TRUNCATE PREFIX_sales_order_tax;
TRUNCATE PREFIX_sales_order_tax_item;
TRUNCATE PREFIX_sendfriend_log; 
TRUNCATE PREFIX_tag; 
TRUNCATE PREFIX_tag_relation; 
TRUNCATE PREFIX_tag_summary; 
TRUNCATE PREFIX_wishlist; 
TRUNCATE PREFIX_log_quote; 
TRUNCATE PREFIX_report_event; 
ALTER TABLE PREFIX_sales_flat_creditmemo AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_flat_creditmemo_comment AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_flat_creditmemo_grid AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_flat_creditmemo_item AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_flat_invoice AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_flat_invoice_comment AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_flat_invoice_grid AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_flat_invoice_item AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_flat_order AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_flat_order_address AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_flat_order_grid AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_flat_order_item AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_flat_order_payment AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_flat_order_status_history AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_flat_quote AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_flat_quote_address AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_flat_quote_address_item AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_flat_quote_item AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_flat_quote_item_option AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_flat_quote_payment AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_flat_quote_shipping_rate AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_flat_shipment AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_flat_shipment_comment AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_flat_shipment_grid AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_flat_shipment_item AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_flat_shipment_track AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_invoiced_aggregated AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_invoiced_aggregated_order AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_payment_transaction AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_order_aggregated_created AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_order_tax AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sales_order_tax_item AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_sendfriend_log AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_tag AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_tag_relation AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_tag_summary AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_wishlist AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_log_quote AUTO_INCREMENT=1; 
ALTER TABLE PREFIX_report_event AUTO_INCREMENT=1; 

SET FOREIGN_KEY_CHECKS = 1;