-- ============================================================
-- 015: 生产环境缺陷修复
-- ============================================================

-- 问题2修复: knowledge_documents 表添加 content 列
SET @col_exists = (SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS
    WHERE TABLE_SCHEMA = 'aiflow' AND TABLE_NAME = 'knowledge_documents' AND COLUMN_NAME = 'content');
SET @sql = IF(@col_exists = 0, 'ALTER TABLE knowledge_documents ADD COLUMN content LONGTEXT DEFAULT NULL AFTER error_message', 'SELECT ''content column already exists'' AS msg');
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;