How does Taobao's shipping module work? Please give me some ideas, teachers and students.

Question

How is Taobao's shipping module made? Please give me some ideas, teachers and students.

For example, my database has

area table fields as follows

id parent_id name

1 0 0 Dongcheng District

2 1 1 Beijing

3 2 Dongcheng District

4 0             Anhui Province

.... ......

How do I make a shipping module like Taobao

For example: Items in Shenzhen

North China Region Free Shipping

Sichuan Chengdu 10 Yuan

Shaanxi Xi'an 11 Yuan

..........

Please give me some ideas and some php to help. Thank you!