-- 存量库：t_order 增加出口资质备案 Id（9610Summary 选用）
-- 可重复执行。

SET @db := DATABASE();

SET @exists := (
  SELECT COUNT(1)
    FROM information_schema.COLUMNS
   WHERE TABLE_SCHEMA = @db
     AND TABLE_NAME = 't_order'
     AND COLUMN_NAME = 'ExportQualificationId'
);

SET @sql := IF(
  @exists = 0,
  'ALTER TABLE `t_order`
     ADD COLUMN `ExportQualificationId` INT NULL COMMENT ''出口资质备案 Id（t_customer_export_qualification.Id）'' AFTER `ExportCustomsMode`,
     ADD KEY `idx_order_export_qualification` (`ExportQualificationId`)',
  'SELECT ''t_order.ExportQualificationId already exists'' AS info'
);

PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;