Question

我试图编写一个SQL查询，在更新另一列时将值设置为1.

具体来说，如果更改了相应的哈希列，我想将is_patch_file设置为1。如果未更改散列列，则应保留当前存储的is_patch_file值。

这可能吗？

表格结构

DROP TABLE IF EXISTS `program_files`;
CREATE TABLE `program_files` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `folder_id` int(10) unsigned NOT NULL,
  `name` varchar(191) COLLATE utf8mb4_unicode_ci NOT NULL,
  `path` varchar(191) COLLATE utf8mb4_unicode_ci NOT NULL,
  `hash` varchar(191) COLLATE utf8mb4_unicode_ci NOT NULL,
  `enabled` tinyint(1) NOT NULL DEFAULT '1',
  `created_at` timestamp NULL DEFAULT NULL,
  `updated_at` timestamp NULL DEFAULT NULL,
  `is_patch_file` tinyint(1) NOT NULL DEFAULT '0',
  PRIMARY KEY (`id`),
  UNIQUE KEY `unique_file` (`folder_id`,`name`,`path`,`hash`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

SQL查询

INSERT INTO program_files (folder_id, name, path, hash, is_patch_file, enabled, created_at, updated_at) VALUES (3, 'TestName', 'TestPath', 'TestHash', 0, 1, NOW(), NOW()) ON DUPLICATE KEY UPDATE 
is_patch_file=1, #Is Patch file should ONLY be 1 if the hash is different from the original hash...otherwise keep our current value how do I do this?
hash=VALUES(hash),
updated_at=VALUES(updated_at);

INSERT INTO program_files (folder_id, name, path, hash, is_patch_file, enabled, created_at, updated_at) VALUES (3, 'TestName', 'TestPath', 'TestHash2', 0, 1, NOW(), NOW()) ON DUPLICATE KEY UPDATE 
is_patch_file=1, #Is Patch file should ONLY be 1 if the hash is different from the original hash...otherwise keep our current value how do I do this?
hash=VALUES(hash),
updated_at=VALUES(updated_at);

Answer 1

您可以在hash更新之前将其与VALUES(hash)进行比较，并在设置is_patch_file时使用它。

ON DUPLICATE KEY UPDATE 
    is_patch_file = hash != VALUES(hash), 
    hash = VALUES(hash), 
    updated_at = VALUES(updated_at)

如果值不同，我如何插入或更新？

1 个答案: