CREATE TABLE IF NOT EXISTS clubs (
 club_serial BIGINT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
 club_name VARCHAR(128) NOT NULL,
 club_status ENUM('active','archived') NOT NULL DEFAULT 'active',
 created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
 UNIQUE KEY (club_name)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
CREATE TABLE IF NOT EXISTS club_memberships (
 membership_serial BIGINT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
 club_serial BIGINT UNSIGNED NOT NULL,
 user_serial BIGINT UNSIGNED NOT NULL,
 membership_status ENUM('active','inactive') NOT NULL DEFAULT 'active',
 joined_on DATE NOT NULL,
 UNIQUE KEY (club_serial,user_serial),
 UNIQUE KEY (membership_serial,club_serial),
 FOREIGN KEY (club_serial) REFERENCES clubs(club_serial) ON DELETE RESTRICT,
 FOREIGN KEY (user_serial) REFERENCES users(user_serial) ON DELETE RESTRICT
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
CREATE TABLE IF NOT EXISTS club_seasons (
 season_serial BIGINT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
 club_serial BIGINT UNSIGNED NOT NULL,
 season_name VARCHAR(100) NOT NULL,
 starts_on DATE NOT NULL,
 ends_on DATE NOT NULL,
 UNIQUE KEY (club_serial,season_name),
 UNIQUE KEY (season_serial,club_serial),
 FOREIGN KEY (club_serial) REFERENCES clubs(club_serial) ON DELETE RESTRICT,
 CHECK (ends_on>=starts_on)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
CREATE TABLE IF NOT EXISTS club_dues (
 due_serial BIGINT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
 club_serial BIGINT UNSIGNED NOT NULL,
 membership_serial BIGINT UNSIGNED NOT NULL,
 season_serial BIGINT UNSIGNED NOT NULL,
 amount_cents BIGINT UNSIGNED NOT NULL,
 created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
 UNIQUE KEY (membership_serial,season_serial),
 FOREIGN KEY (membership_serial,club_serial) REFERENCES club_memberships(membership_serial,club_serial) ON DELETE RESTRICT,
 FOREIGN KEY (season_serial,club_serial) REFERENCES club_seasons(season_serial,club_serial) ON DELETE RESTRICT
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
CREATE TABLE IF NOT EXISTS club_payments (
 payment_serial BIGINT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
 due_serial BIGINT UNSIGNED NOT NULL,
 amount_cents BIGINT UNSIGNED NOT NULL,
 paid_on DATE NOT NULL,
 request_key CHAR(64) CHARACTER SET ascii COLLATE ascii_bin NOT NULL UNIQUE,
 created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
 FOREIGN KEY (due_serial) REFERENCES club_dues(due_serial) ON DELETE RESTRICT,
 CHECK (amount_cents>0)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;