MYSQL更新语句内部连接表

我不知道是什么问题。 使用MySQL 5.0我试图运行下面的MYSQL更新语句时出现编译错误

UPDATE b SET b.mapx = g.latitude, b.mapy = g.longitude FROM business AS b INNER JOIN business_geocode g ON b.business_id = g.business_id WHERE (b.mapx = '' or b.mapx = 0) and g.latitude > 0 

所有的字段名称都是正确的。 有什么想法吗？

Answer 1

尝试这个：

 UPDATE business AS b INNER JOIN business_geocode AS g ON b.business_id = g.business_id SET b.mapx = g.latitude, b.mapy = g.longitude WHERE (b.mapx = '' or b.mapx = 0) and g.latitude > 0 

更新：

既然你说查询产生了一个语法错误，我创build了一些表，我可以testing它并确认在我的查询中没有语法错误：

 mysql> create table business (business_id int unsigned primary key auto_increment, mapx varchar(255), mapy varchar(255)) engine=innodb; Query OK, 0 rows affected (0.01 sec) mysql> create table business_geocode (business_geocode_id int unsigned primary key auto_increment, business_id int unsigned not null, latitude varchar(255) not null, longitude varchar(255) not null, foreign key (business_id) references business(business_id)) engine=innodb; Query OK, 0 rows affected (0.01 sec) mysql> UPDATE business AS b -> INNER JOIN business_geocode AS g ON b.business_id = g.business_id -> SET b.mapx = g.latitude, -> b.mapy = g.longitude -> WHERE (b.mapx = '' or b.mapx = 0) and -> g.latitude > 0; Query OK, 0 rows affected (0.00 sec) Rows matched: 0 Changed: 0 Warnings: 0 

看到？ 没有语法错误。 我testing了MySQL 5.5.8。

Answer 2

SET子句应该在表规范之后。

 UPDATE business AS b INNER JOIN business_geocode g ON b.business_id = g.business_id SET b.mapx = g.latitude, b.mapy = g.longitude WHERE (b.mapx = '' or b.mapx = 0) and g.latitude > 0