Question

有以下问题

INSERT INTO statistics_new (SELECT * FROM statistics)
    -> 
    -> ON DUPLICATE KEY UPDATE
    -> 
    -> end_date = IF(end_date < VALUES(end_date), VALUES(end_date), end_date);
ERROR 1052 (23000): Column 'end_date' in field list is ambiguous

当我尝试按照http://dev.mysql.com/doc/refman/5.0/en/insert-select.html中的建议指定列和表别名时，我得到了相同的结果。

服务器版本：5.5.24-0ubuntu0.12.04.1（Ubuntu）

以下查询运行没有问题：

INSERT INTO statistics_new (SELECT * FROM statistics)
ON DUPLICATE KEY UPDATE
end_date = VALUES(end_date)

Answer 1

SQLFiddle example

基本上我认为你想要这个：

INSERT INTO statistics_new (SELECT * FROM statistics)
ON DUPLICATE KEY UPDATE
statistics_new.end_date = if(statistics_new.end_date < statistics.end_date, 
                             statistics.end_date, statistics_new.end_date);

Answer 2

statistics_new和statistics都有end_date列。请在SQL中区分它们。

Answer 3

如果你试图在最后一行设置一个变量，那应该是：

SET @end_date = IF(end_date < VALUES(end_date), VALUES(end_date), end_date);

MySQL键ON DUPLICATE KEY UPDATE列不明确

3 个答案: