-- 为 t_activity_player 表添加 region_id 字段
ALTER TABLE t_activity_player 
ADD COLUMN region_id bigint DEFAULT NULL COMMENT '区域ID，关联t_region表' 
AFTER player_id;

-- 添加外键约束
ALTER TABLE t_activity_player 
ADD CONSTRAINT fk_activity_player_region 
FOREIGN KEY (region_id) REFERENCES t_region(id) 
ON DELETE SET NULL ON UPDATE CASCADE;

-- 验证字段添加
DESCRIBE t_activity_player;