-- ============================================================
-- Migration: biz_expert.status 0/1 → Y/N
-- Date: 2026-08-16
-- Author: Claude
-- 影响范围: biz_expert 表的 status 字段
-- 旧语义: '0' = 正常, '1' = 禁用
-- 新语义: 'Y' = 正常, 'N' = 禁用
-- 注意: audit_status (0/1/2) 不变
-- ============================================================

-- 0. 备份 (可选, 已上生产前一定要做)
-- CREATE TABLE biz_expert_status_bak_20260816 AS
--   SELECT expert_id, status FROM biz_expert;

-- 1. 数据迁移 (先转换旧值, 避免默认值变化后插入冲突)
UPDATE biz_expert SET status = 'Y' WHERE status = '0';
UPDATE biz_expert SET status = 'N' WHERE status = '1';

-- 2. 表结构变更 (默认值 + 注释)
ALTER TABLE biz_expert
  MODIFY COLUMN status CHAR(1) DEFAULT 'Y' COMMENT '状态 Y正常 N禁用';

-- 3. 验证 (执行后应全部为 Y/N)
-- SELECT status, COUNT(*) FROM biz_expert GROUP BY status;
-- 预期结果:
--   Y | 10
--   N | 0