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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