如何使用加入和分组进行更新？

Question

我想做这样的查询：

UPDATE State
LEFT JOIN Actions ON Actions.id = State.id
SET duration = FLOOR(AVG(duration)) WHERE type = 'started' GROUP BY Actions.id

我该怎么做？ （它表示分组是错误的）

Answer 1

UPDATE State
INNER JOIN 
(
   select id, FLOOR(AVG(duration)) as avg
   from Actions
   WHERE type = 'started'
   group by id        
) tmp ON tmp.id = State.id
SET duration = tmp.avg

Answer 2

简短回答是：

UPDATE状态LEFT JOIN操作ON Actions.id = State.id SET duration = FLOOR（AVG（duration））WHERE Actions.id IN（从Actions中选择id，其中Actions.id = state.id和type ='started'GROUP BY Actions.id）

可能在语法上不太正确。