Question

我在mysql程序中有这一行

UPDATE mytable SET product_code =  p_code  WHERE  mytable.product_id=p_id ;

它产生了这个错误：

Error Code: 1054. Unknown column product_code in 'field list'

我不明白这是什么问题？为什么会出现这个错误？

更新：表结构如下：

CREATE TABLE `mytable` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `email` varchar(255) NOT NULL,
  `password` varchar(100) NOT NULL,
  `product_id` int(11) NOT NULL,
  `another_id` int(11) NOT NULL DEFAULT '1',
  `forein_key` int(11) NOT NULL DEFAULT '2',
  `create_date` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `update_date` timestamp NULL DEFAULT NULL ON UPDATE CURRENT_TIMESTAMP,
  `some_other_field` int(11) NOT NULL DEFAULT '0',
  `other_field` datetime DEFAULT NULL,
  `product_code` varchar(20) DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `email` (`email`,`another_id`,`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3553 DEFAULT CHARSET=latin1;

步骤：

DROP PROCEDURE IF EXISTS UPDATE_PRODUCT_ID $$

CREATE PROCEDURE UPDATE_PRODUCT_ID()
BEGIN
DECLARE n INT DEFAULT 0;
DECLARE i INT DEFAULT 0;
DECLARE p_code varchar(20);
DECLARE p_id int(11);
DECLARE cur1 CURSOR FOR SELECT product_id, product_code FROM product;
SET SQL_SAFE_UPDATES = 0;
SELECT COUNT(*) FROM product INTO n;
SET i=0;
OPEN cur1;
WHILE i<n DO
    FETCH cur1 INTO p_id, p_code;
    UPDATE mytable SET mytable.product_code =  p_code  WHERE  mytable.product_id=p_id ;
  SET i = i + 1;
END WHILE;
SET SQL_SAFE_UPDATES = 1;
End $$

DELIMITER ;

CALL UPDATE_PRODUCT_ID();

错误代码：1054。未知的列product_code在＆＃39;字段列表＆＃39;

0 个答案: