Sql 使用EXTO查询连接3个表

下面是一个关于

Postgres查询：

SELECT * FROM
(hearings LEFT JOIN hearing_category_link ON hearings.hearing_id = hearing_category_link.hearing_id )
LEFT JOIN categories ON hearing_category_link.category_id = categories.category_id

到目前为止，我只能用一个表连接当前查询

from h in "hearings", join: hl in "hearing_category_link", on: hl.hearing_id == h.hearing_id

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但是我想使用EXTO连接这3个表，并动态地获得结果，这将是非常棒的

您只需编写两个连接：

from hearing in "hearings",
  join: hcl in "hearing_category_link", on: hcl.hearing_id == hearing.id,
  join: category in "categories", on: hcl.category_id == category.id

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您只需编写2个联接：

from hearing in "hearings",
  join: hcl in "hearing_category_link", on: hcl.hearing_id == hearing.id,
  join: category in "categories", on: hcl.category_id == category.id