Mysql 不等于运算符失败？

Question

我有以下 mysql table（简体）：

CREATE TABLE IF NOT EXISTS `mytable` (
`id` int(11) unsigned NOT NULL AUTO_INCREMENT,
`emails` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
`phones` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
`history` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,

PRIMARY KEY (`id`),
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci AUTO_INCREMENT=259 ;

我有以下查询：

SELECT *
FROM mytable
WHERE emails LIKE '%addr@yahoo.com%'
OR phones LIKE '%addr@yahoo.com%'
AND history !='None'

这产生了 2 条记录：

INSERT INTO `mytable` (`id`, `emails`, `phones`, `history`) VALUES
(118, 'PLEASE SET', NULL, 0, 'addr@yahoo.com', NULL, 0, 'None'),
(237, 'PLEASE SET', NULL, 0, 'addr@yahoo.com', NULL, 0, 'gomez');

但我原以为带有 history = 'None' 的那个不会被包括在内。我做错了什么？

Answer 1

您应该在 WHERE 子句中明确设置括号：

WHERE (all_emails LIKE '%addr@yahoo.com%'
   OR all_phones LIKE '%addr@yahoo.com%')
  AND history !='None'

Answer 2

在 ()

中整理您的 OR 标准

SELECT *
FROM mytable
WHERE (all_emails LIKE '%addr@yahoo.com%'
OR all_phones LIKE '%addr@yahoo.com%')
AND history !='None

Sample Demo

Answer 3

SELECT *
FROM mytable
WHERE (all_emails LIKE '%addr@yahoo.com%'
OR all_phones LIKE '%addr@yahoo.com%')
AND history NOT IN(
SELECT history FROM mytable WHERE history LIKE 'None')

Mysql 不等于运算符失败？

Mysql not equal operator failing?

mysql

sql