-- =============================================================
-- 附件表补齐「文件存储分层」改造字段与索引：yz_system_files
-- 变更：
--   source      varchar(16) NOT NULL DEFAULT 'backend'  来源端 backend-租户后台 platform-平台端
--   scope       varchar(16) NOT NULL DEFAULT 'tenant'   归属 tenant-租户共享 user-用户个人
--   storage     varchar(16) NOT NULL DEFAULT ''         存储类型 local/qiniu
--   object_key  varchar(512) NOT NULL DEFAULT ''        存储相对路径(不含域名)
--   idx_file_dedup (source, scope, tid, tuid, md5(32))  MD5 精确去重
--   idx_file_owner (source, tid, scope, tuid, delete_time) 归属列表过滤
-- 注意：
--   1. md5 在部分历史库中是 TEXT 类型，MySQL 不允许对 TEXT/BLOB 建整列索引，
--      故索引使用前缀长度 md5(32)（MD5 十六进制串固定 32 字符）。
--   2. 本脚本可重复执行：列/索引不存在时才执行 ALTER，已存在自动跳过（不再报 1060/1061）。
-- 运行：mysql -h<host> -P<port> -u<user> -p <db> < alter_system_files_storage_columns.sql
-- =============================================================

-- source：来源端
SET @tbl := (SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'yz_system_files');
SET @col := (SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'yz_system_files' AND COLUMN_NAME = 'source');
SET @ddl := IF(@tbl > 0 AND @col = 0, 'ALTER TABLE `yz_system_files` ADD COLUMN `source` varchar(16) NOT NULL DEFAULT ''backend'' COMMENT ''来源端: backend-租户后台 platform-平台端''', 'DO 0');
PREPARE stmt FROM @ddl; EXECUTE stmt; DEALLOCATE PREPARE stmt;

-- scope：归属
SET @tbl := (SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'yz_system_files');
SET @col := (SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'yz_system_files' AND COLUMN_NAME = 'scope');
SET @ddl := IF(@tbl > 0 AND @col = 0, 'ALTER TABLE `yz_system_files` ADD COLUMN `scope` varchar(16) NOT NULL DEFAULT ''tenant'' COMMENT ''归属: tenant-租户共享 user-用户个人''', 'DO 0');
PREPARE stmt FROM @ddl; EXECUTE stmt; DEALLOCATE PREPARE stmt;

-- storage：存储类型
SET @tbl := (SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'yz_system_files');
SET @col := (SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'yz_system_files' AND COLUMN_NAME = 'storage');
SET @ddl := IF(@tbl > 0 AND @col = 0, 'ALTER TABLE `yz_system_files` ADD COLUMN `storage` varchar(16) NOT NULL DEFAULT '''' COMMENT ''存储类型: local/qiniu''', 'DO 0');
PREPARE stmt FROM @ddl; EXECUTE stmt; DEALLOCATE PREPARE stmt;

-- object_key：存储相对路径
SET @tbl := (SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'yz_system_files');
SET @col := (SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'yz_system_files' AND COLUMN_NAME = 'object_key');
SET @ddl := IF(@tbl > 0 AND @col = 0, 'ALTER TABLE `yz_system_files` ADD COLUMN `object_key` varchar(512) NOT NULL DEFAULT '''' COMMENT ''存储相对路径(不含域名)''', 'DO 0');
PREPARE stmt FROM @ddl; EXECUTE stmt; DEALLOCATE PREPARE stmt;

-- idx_file_dedup：MD5 精确去重索引
SET @tbl := (SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'yz_system_files');
SET @idx := (SELECT COUNT(*) FROM INFORMATION_SCHEMA.STATISTICS WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'yz_system_files' AND INDEX_NAME = 'idx_file_dedup');
SET @ddl := IF(@tbl > 0 AND @idx = 0, 'ALTER TABLE `yz_system_files` ADD KEY `idx_file_dedup` (`source`, `scope`, `tid`, `tuid`, `md5`(32))', 'DO 0');
PREPARE stmt FROM @ddl; EXECUTE stmt; DEALLOCATE PREPARE stmt;

-- idx_file_owner：归属列表过滤索引
SET @tbl := (SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'yz_system_files');
SET @idx := (SELECT COUNT(*) FROM INFORMATION_SCHEMA.STATISTICS WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'yz_system_files' AND INDEX_NAME = 'idx_file_owner');
SET @ddl := IF(@tbl > 0 AND @idx = 0, 'ALTER TABLE `yz_system_files` ADD KEY `idx_file_owner` (`source`, `tid`, `scope`, `tuid`, `delete_time`)', 'DO 0');
PREPARE stmt FROM @ddl; EXECUTE stmt; DEALLOCATE PREPARE stmt;