SELECT 返回数据，但 UPDATE 给出受影响的行：0

Question

这是数据：

CREATE TABLE `Charlies_Sierra_Papa` (
  `Mike` int(5) default NULL,
  `cpf` char(11) default NULL,
  `idFoxtrot` int(3) default NULL,

) ENGINE=MyISAM AUTO_INCREMENT=254098 DEFAULT CHARSET=utf8;

INSERT INTO `Charlies_Sierra_Papa` VALUES ('1', '12345678910', '12');
INSERT INTO `Charlies_Sierra_Papa` VALUES ('2', '11121314157', '12');
INSERT INTO `Charlies_Sierra_Papa` VALUES ('3', '57585960610', '12');


CREATE TABLE `Charlies` (
  `idCharlie` int(20) NOT NULL auto_increment,
  `cpf` varchar(11) NOT NULL default ''
  PRIMARY KEY  (`idCharlie`),
  UNIQUE KEY `cpf` (`cpf`),
  UNIQUE KEY `idCharlie` (`idCharlie`),
) ENGINE=MyISAM AUTO_INCREMENT=264670 DEFAULT CHARSET=latin1;

INSERT INTO `Charlies` VALUES ('1', '12345678910');
INSERT INTO `Charlies` VALUES ('2', '11121314157');
INSERT INTO `Charlies` VALUES ('3', '57585960610');


CREATE TABLE `Mike` (
  `Mike` int(5) unsigned zerofill NOT NULL auto_increment,
  `idCharlie` int(11) NOT NULL default '0',
  PRIMARY KEY  (`Mike`),
  UNIQUE KEY `idCharlie` (`idCharlie`)
) ENGINE=MyISAM AUTO_INCREMENT=12043 DEFAULT CHARSET=latin1;

INSERT INTO `Mike` VALUES ('00001', '51214');
INSERT INTO `Mike` VALUES ('00002', '174135');
INSERT INTO `Mike` VALUES ('00003', '203553');

这是 SELECT 和 UPDATE：

UPDATE Charlies_Sierra_Papa AS csp, Charlies AS Cha, Mike_oc AS Mik
SET csp.cpf = cast(Cha.cpf AS char(11))
WHERE csp.cpf = Cha.cpf
AND Cha.idCharlie = Mik.idCharlie
AND csp.Mike = Mik.Mike
AND csp.idFoxtrot = 16 


SELECT * FROM Charlies_Sierra_Papa AS csp, Charlies AS Cha, Mike_oc AS Mik
/*SET csp.cpf = cast(Cha.cpf AS char(11))*/
WHERE csp.cpf = Cha.cpf
AND Cha.idCharlie = Mik.idCharlie
AND csp.Mike = Mik.Mike
AND csp.idFoxtrot = 16 

我的问题是：SELECT 返回预期值，但是当我运行它时，UPDATE 给了我一个恼人的“Affected rows: 0”。

有什么线索吗？

Answer 1

这是一个微不足道的错误：

我正在尝试更新 csp.cpf = Cha.cpf
但我也绑定 csp.cpf = Cha.cpf
所以，没有更新行，也没有雪茄。