Magento obtiene el teléfono del cliente por sql

Magento is based on EAV architectur So if you take a look at eav_attribute table you'll see that telephone attribute is a varchar and the entity_type_id is 2 (it mean it's a customer address attribute) You Sql request may look like :

select customer_address_entity_varchar.value from customer_address_entity_varchar
left join  customer_entity on customer_entity.entity_id = "your_customer_id"
left join  customer_address_entity on customer_address_entity.parent_id = customer_entity.entity_id
join eav_attribute on eav_attribute.attribute_code="telephone"
where customer_address_entity_varchar.attribute_id = eav_attribute.attribute_id