Question

我正在尝试执行此查询，似乎它返回错误：

INSERT INTO `categories` (`name`,`path`) VALUES ('TEST 1' , 'test-1'),('TEST 2' , 'test-2'),('TEST 3' , 'test-3')
WHERE (`name`,`path`) NOT IN (SELECT `name`,`path` FROM `categories`);

对此有何帮助？非常感谢。

Answer 1

您尝试的逻辑是使用如下语法实现的：

INSERT INTO `categories` (`name`,`path`)
     SELECT name, path
     FROM (SELECT 'TEST 1' as name, 'test-1' as path UNION ALL
           SELECT 'TEST 2', 'test-2' UNION ALL
           SELECT 'TEST 3' , 'test-3'
          ) t
     WHERE NOT EXISTS (SELECT 1
                       FROM categories c
                       WHERE c.name = t.name and c.path = t.path
                      );

但是，您应该使用唯一索引在数据库中进行检查。因此，更好的解决方案是进行插入，只需：

create unique index idx_categories_name_path on categories(name, path)

使用insert之类的：

INSERT INTO `categories` (`name`,`path`)
     SELECT name, path
     FROM (SELECT 'TEST 1' as name, 'test-1' as path UNION ALL
           SELECT 'TEST 2', 'test-2' UNION ALL
           SELECT 'TEST 3' , 'test-3'
          ) t
     ON DUPLICATE KEY UPDATE name = VALUES(name);

插入多行而不重复它们 - MySQL

1 个答案: