UPDATE customer_entity
LEFT JOIN sales_order ON customer_entity.entity_id=sales_order.customer_id AND (sales_order.subtotal IS NULL OR sales_order.subtotal=0)
SET customer_entity.group_id = 56
WHERE customer_entity.group_id=1
感谢 http://blog.csdn.net/defonds/article/details/46745143
原文：http://www.cnblogs.com/fengliang/p/6121242.html