PHP Small White related issues

Ask for PHP small white question
There are now three of tables
Hotel table area name low season price peak season price flat season price star
Regional Quotation table section of the line area of the ticket fee fee for the number of nights you can choose to stay in the hotel collection (mainly hotel star different)
Route table field name path Region collection

The logical relationship between them is

A route to each region, in each region needs to spend (the regional price table of meals, fares, tickets, hotel fees), about the hotel costs this piece, in each region there are three hotels (3,4,5 three levels), each level of different prices, and each hotel also light peak season prices

Now to calculate the total price of the Line table, according to the hotel's level and light season difference, so that the total price of the line has 9!

For prawn support, and now do statistics hotel total cost of this piece is a headache
I don't know if my expression is clear!

------Solution--------------------
A LEFT join can be used in a continuous sense.

