sql - Condition in Mysql while selecting data form different tables -

i have code , working perfectly, have added 2 new columns in orders table in database:

• guest_user ('y'/'n')

• guest_phone

what want if guest_user 'y' don't have users.email replace orders.guest_phone.

how this. can fix please....

 select distinct     orders.id 'order id',     users.email 'email',     orders.price 'amount',     orders.city_sj 'city',     orders.order_from 'web/app',     orders.payment_status 'cod/pwc',     orders. @ 'date , time'  users, orders, order_history      users.id = order_history.uid   , orders.id = order_history.oid   , orders. real = 1   , orders.price > 1   , orders. status = 1 order orders.id; 

running above code getting below type of output:

enter image description here

thanks

something should job want:

select distinct orders.id 'order id',          if(orders.guest_user = 'y', orders.guest_phone, users.email) 'phone/email',          orders.price 'amount', orders.city_sj 'city',        orders.order_from 'web/app',         orders.payment_status 'cod/pwc',         orders.at 'date , time' users join order_history on users.id = order_history.uid   join orders on orders.id= order_history.oid orders.real=1 , orders.price>1 , orders.status=1 order orders.id; 

you should use explicit join syntax instead of old style implicit style.