xshop/docs/6-state-city.md

State and City Models

The State and City models are designed to manage geographical data within your application. These models allow for the organization of locations, enabling functionalities related to regional management of users, services, or logistics.

State Model

The State model represents a geographical region within a country and serves as a parent for the City model.

Fields Description

1. id

• Type: Integer
• Description: A unique identifier for each state. This field is automatically generated and serves as the primary key for the model.

2. name

• Type: Text
• Description: The name of the state. This field is required.

3. lat

• Type: Double
• Description: The latitude coordinate of the state, which can be useful for mapping and geographical calculations.

4. lng

• Type: Double
• Description: The longitude coordinate of the state, complementing the latitude for precise geographical representation.

5. country

• Type: Text
• Description: The name of the country that the state belongs to. This field is essential for understanding the geographical context of the state.

Summary

The State model provides a structured representation of states within a country, including essential geographical coordinates and country affiliation.

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City Model

The City model represents urban areas within a state and establishes a relationship with the State model.

Fields Description

1. id

• Type: Integer
• Description: A unique identifier for each city. This field is automatically generated and serves as the primary key for the model.

2. name

• Type: Text
• Description: The name of the city. This field is required.

3. lat

• Type: Double (Nullable)
• Description: The latitude coordinate of the city, which can be useful for mapping and location services.

4. lng

• Type: Double (Nullable)
• Description: The longitude coordinate of the city, providing necessary details for accurate location mapping.

5. state_id

• Type: Unsigned Big Integer
• Description: The ID of the state to which this city belongs. This establishes a foreign key relationship with the State model, linking cities to their respective states.

Summary

The City model complements the State model by providing a detailed structure for managing cities within specific states. It allows for clear organization of geographical data, essential for functionalities requiring location-based services.

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Relationship Between State and City

• Each State can have multiple associated City records, establishing a one-to-many relationship.
• The City model includes a foreign key (state_id) that links each city to its respective state.

By integrating the State and City models, your application can effectively manage geographical data, facilitating the organization of regional information for users and services.