Sql Postgres-如何在更新子查询中引用外部表？

我正在尝试做如下事情：

UPDATE table1
SET table1.nearest_city_id = subquery.id
FROM 
  (SELECT id FROM cities ORDER BY cities.location <-> table1.location LIMIT 1)
  AS subquery;

i、 e.根据空间查询在表1中设置最近的城市

但我无法在子查询中引用正在更新的行。有没有办法解决这个问题？

类似这样的问题：

UPDATE table1
  SET nearest_city_id = (select id
                         from cities c
                         ORDER BY c.location <-> table1.location
                         LIMIT 1);

大概是这样的：

UPDATE table1
  SET nearest_city_id = (select id
                         from cities c
                         ORDER BY c.location <-> table1.location
                         LIMIT 1);

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如果需要按一个条件更新表1的1列和表2的1列：

UPDATE Table1 
 SET Table1.Column = A.Column 
      FROM(SELECT Column,Id FROM Table2) As A
 WHERE Table1.Id=Table2.Id

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如果需要按一个条件更新表1的1列和表2的1列：

UPDATE Table1 
 SET Table1.Column = A.Column 
      FROM(SELECT Column,Id FROM Table2) As A
 WHERE Table1.Id=Table2.Id

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@一匹没有名字的马我同意：删除。@一匹没有名字的马我同意：删除。