-- ============================================
-- BAYAZID FARM MANAGEMENT SYSTEM
-- Soft-delete / Archive support for cows
-- Run this once after schema.sql
-- (Per spec: never hard-delete a cow record — archive instead)
-- ============================================

USE technica_bayezid;

ALTER TABLE cows ADD COLUMN archived_at DATETIME NULL DEFAULT NULL AFTER status;
ALTER TABLE cows ADD COLUMN archived_by INT NULL DEFAULT NULL AFTER archived_at;
ALTER TABLE cows ADD CONSTRAINT fk_cows_archived_by FOREIGN KEY (archived_by) REFERENCES users(id) ON DELETE SET NULL;

CREATE INDEX idx_cows_archived ON cows(archived_at);