Store postal codes as strings rather than integers to prevent the system from dropping critical leading zeros (such as the 0 in 015107 ).
CREATE TABLE user_addresses ( id SERIAL PRIMARY KEY, street_address VARCHAR(255), city VARCHAR(100), state_province VARCHAR(100), -- Always use VARCHAR for postal codes to keep leading zeros postal_code VARCHAR(12) NOT NULL, country_code CHAR(2) NOT NULL ); Use code with caution. Copied to clipboard 4. API Response Model (JSON) 015107 zip
: Use the entered code to instantly suggest the corresponding city and country. 2. Regex Validation Rules Store postal codes as strings rather than integers
Apply these conditional regular expression constraints depending on the detected or selected country: Code Example Regex Pattern 015107 ^[0-9]{6}$ United States 90210 ^[0-9]{5}$ United States (ZIP+4) 90210-4321 10 Characters ^[0-9]{5}-[0-9]{4}$ 3. Database Schema (PostgreSQL Example) API Response Model (JSON) : Use the entered
This technical feature enables your application to accept, parse, and validate both 5-digit US ZIP codes and 6-digit international postal codes (like China's 015107 ) without failing. 1. User Interface (UI) Behavior : Create a single "Postal / ZIP Code" text field.
When a user queries the system for code 015107 , the backend should return a mapped geographic payload: