第7课 创建计算字段拼接字段执行简单的算术运算

select concat((vend_name),'(',rtrim(vend_country),')')
from vendors
order by vend_name;

select concat((vend_name),'(',rtrim(vend_country),')')
as vend_title
from vendors
order by vend_name;

select prod_id,
quantity,
item_price,
quantity *item_price as expanded_price
from orderitems
where order_num = 20008;