mysql REPLACE INTO只有一些字段

表

CREATE TABLE `gfs` (
    `localidad` varchar(20),
    `fecha` datetime,
    `pp` float(8,4) NOT NULL default '0.0000',
    `temp` float(8,4) NOT NULL default '0.0000',
    PRIMARY KEY (`localidad`,`fecha`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1;

当我尝试使用此更新字段时

REPLACE INTO gfs(localidad,fecha,pp) VALUES ("some_place","2012-08-05 02:00","1.6")

先前的值en temp将丢失.为什么？

所记载并且其他人已经提到过：

07001 is a MySQL extension to the SQL standard. It either inserts, or deletes and inserts. For another MySQL extension to standard SQL—that either inserts or updates—see 07002.

手册继续解释：

Values for all columns are taken from the values specified in the REPLACE statement. Any missing columns are set to their default values, just as happens for INSERT . You cannot refer to values from the current row and use them in the new row.

因此,你想要：

INSERT INTO gfs (localidad, fecha, pp)
VALUES ('some_place', '2012-08-05 02:00', 1.6)
ON DUPLICATE KEY UPDATE pp=VALUES(pp);