Urban Database design Process

City functions

City superlative

Other states of China (demo)

City lowest level

(Limit the city of the task to this level)

Database

Database fields

Use

Location City: state-City. Name, Data_level,

Derive the popular: number of searches. China-China +1; Guangzhou-Guangzhou +1;

Import data

Manually import major cities in China, major cities in the Americas

At last

Consider how to automatically import

Database relationships

City Table Relationship

Self-join foreign key relationships

Relationship between recruit and city table

Many-to-many

Passing to the front end

Tree structures in domestic and other states

Resident City

Many-to-many

Mission City

Many-to-many

Search process

Single City

1. Incoming city= China
2. Search City = City.object.filter (city= ' China ')
3. Expand city to the lowest level, here for all cities in China
4. Search for tasks that contain the city

Multiple cities

1. Incoming city= China | Japan
2. Find out China, Japan
3. Expand China, Japan to a set inside
4. The mission that contains the city

Urban Database design Process