-- 添加 oauth_state 列到 channels 表（用于微信ClawBot扫码授权状态管理）
-- MySQL 8 不支持 ADD COLUMN IF NOT EXISTS，使用存储过程实现幂等
SET @dbname = DATABASE();
SET @tablename = 'channels';
SET @columnname = 'oauth_state';
SET @preparedStatement = (SELECT IF(
  (SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS
   WHERE TABLE_SCHEMA = @dbname
     AND TABLE_NAME = @tablename
     AND COLUMN_NAME = @columnname) > 0,
  'SELECT 1',
  'ALTER TABLE channels ADD COLUMN oauth_state VARCHAR(500) DEFAULT NULL'
));
PREPARE stmt FROM @preparedStatement;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;