Please help
I have a SQL query
SELECT c.id_customer, c.firstname, c.lastname, count (o.id_order) AS ordercnt FROM pslh_customer c LEFT JOIN pslh_orders o ON c.id_customer = o.id_customer GROUP BY o.id_customer
gets data from 2 tables pslh_customer and pslh_orders and returns first name, last name, numberorders
I need to add a phone number from the third table, pslh_address, phone field
for result
as id_customer firstname lastname ordercnt phone
1 John DOE 5 666666666
2 Me because 1 666666666
I can't connect 3 tables 
in the final step , I need to create a php file that connects to the database, executing this query and displaying the result