-- 为预览标记增加原文位置字段（[70-73] 展开为 4 条时共用 cite_tag_* / text_*）
ALTER TABLE `t_reference_check_result`
  ADD COLUMN `cite_tag_start` int(11) NOT NULL DEFAULT 0 COMMENT 'blue标签起始字节偏移' AFTER `reference_raw`,
  ADD COLUMN `cite_tag_end` int(11) NOT NULL DEFAULT 0 COMMENT 'blue标签结束字节偏移' AFTER `cite_tag_start`,
  ADD COLUMN `text_start` int(11) NOT NULL DEFAULT 0 COMMENT '引用句起始字节偏移' AFTER `cite_tag_end`,
  ADD COLUMN `text_end` int(11) NOT NULL DEFAULT 0 COMMENT '引用句结束字节偏移' AFTER `text_start`,
  ADD KEY `idx_am_cite` (`am_id`,`cite_tag_start`,`reference_no`);