MySQL-如果尚不存在则插入 [英] MySQL - insert if doesn't exist yet

问题描述

我要执行此MySQL查询:

I want to execute this MySQL query:

INSERT INTO `cron-stats` (`user`) VALUES (".(int)$d['by-user'].")

每当不存在这样的用户时，例如:

Whenever such user doesn't exist yet, as in:

SELECT 1
FROM `cron-stats`
WHERE `user` = ".(int)$d['by-user']."

如何在一个查询中执行此操作?

How can I execute this in one query?

推荐答案

您可以使用ON DUPLICATE KEY UPDATE

INSERT INTO `cron-stats` (`user`) VALUES ('yourValue')
ON DUPLICATE KEY UPDATE user = user;

• 重复键更新
• ON DUPLICATE KEY UPDATE

，但是为了更好地执行INSERT语句，您需要在列user上设置UNIQUE索引.

but in order to perform the INSERT statement well, you need to set a UNIQUE index on column user.

如果该列还没有index，请执行以下语句，

if the column has no index yet, execute the statement below,

 ALTER TABLE `cron-stats` ADD CONSTRAINT tb_un UNIQUE (`user`)

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