未知栏＆＃39; a1.location＆＃39;在＆＃39; where子句＆＃39;

Question

我正在尝试执行此查询

UPDATE airport AS a1, 
(SELECT location_ar 
FROM airport as a3 
WHERE a3.location = a1.location AND a3.location_ar != NULL LIMIT 1) as a2 
SET a1.location_ar = a2.location_ar WHERE a1.location = NULL;

但即时通讯＆＃34;未知专栏＆＃39; a1.location＆＃39;在＆＃39; where子句＆＃39;＆＃34;，

已编辑：新查询为：

UPDATE airport AS a1, (SELECT location_ar FROM airport WHERE location = a1.location AND a3.location_ar != NULL LIMIT 1) as a2 SET a1.location_ar = a2.location_ar WHERE a1.location = NULL;

请帮助

Answer 1

更好的方法是使用join

update airport a1
join airport a2 on a1.location = a2.location and a2.location_ar is not NULL
set a1.location_ar = a2.location_ar
where a1.location is NULL;

Answer 2

试试吧。

UPDATE airport AS a1, 
(SELECT location_ar FROM airport as a3 
 WHERE a3.location = airport.location 
 AND a3.location_ar is not NULL LIMIT 1) as a2 
 SET a1.location_ar = a2.location_ar 
 WHERE a1.location is NULL;