-- UTF-8 Encoding für deutsche Sonderzeichen sicherstellen SET client_encoding = 'UTF8'; CREATE TABLE IF NOT EXISTS customers ( id SERIAL PRIMARY KEY, name TEXT NOT NULL, email TEXT, created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ); CREATE TABLE IF NOT EXISTS licenses ( id SERIAL PRIMARY KEY, license_key TEXT UNIQUE NOT NULL, customer_id INTEGER REFERENCES customers(id), license_type TEXT NOT NULL, valid_from DATE NOT NULL, valid_until DATE NOT NULL, is_active BOOLEAN DEFAULT TRUE ); CREATE TABLE IF NOT EXISTS sessions ( id SERIAL PRIMARY KEY, license_id INTEGER REFERENCES licenses(id), session_id TEXT UNIQUE NOT NULL, ip_address TEXT, user_agent TEXT, started_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP, last_heartbeat TIMESTAMP DEFAULT CURRENT_TIMESTAMP, ended_at TIMESTAMP, is_active BOOLEAN DEFAULT TRUE );