如果已经存在，如何插入记录或更新?

How to INSERT a record or UPDATE if it already exists?(如果已经存在，如何插入记录或更新?)

问题描述

我有一张表，其中包含 record_id (auto inc)、sender、sent_time 和 status 列.

I have a table with columns record_id (auto inc), sender, sent_time and status.

如果没有特定发件人的任何记录，例如sender1"，我必须插入一条新记录，否则我必须更新属于user1"的现有记录.

In case there isn't any record of a particular sender, for example "sender1", I have to INSERT a new record otherwise I have to UPDATE the existing record which belongs to "user1".

所以如果没有任何记录已经存储，我会执行

So if there isn't any record already stored, I would execute

# record_id is AUTO_INCREMENT field
INSERT INTO messages (sender, sent_time, status)
VALUES (@sender, time, @status)

否则我会执行 UPDATE 语句.

Otherwise I would execute UPDATE statement.

无论如何.. 如果没有字段发件人值为user1"的任何记录，是否有人知道如何组合这两个语句以插入新记录，否则更新现有记录?

Anyway.. does anyone know how to combine these two statements in order to insert a new record if there isn't any record where the field sender value is "user1" otherwise update the existing record?

推荐答案

MySQL支持insert-on-duplicate 语法，fe:

MySQL supports the insert-on-duplicate syntax, f.e.:

INSERT INTO table (key,col1) VALUES (1,2)
  ON DUPLICATE KEY UPDATE col1 = 2;

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