我正在使用 papertrail gem 来跟踪我的问题和结果模型的版本。
我可以成功订购 Papertrail::Versions,如下所示:
PaperTrail::Version.order(created_at: :desc).limit(1).select(:id)
PaperTrail::Version Load (0.3ms) SELECT "versions"."id" FROM "versions" ORDER BY "versions"."created_at" DESC LIMIT $1 [["LIMIT", 1]]
=> [#<PaperTrail::Version:0x00007f4d90820f20 id: 32>]
PaperTrail::Version.order(created_at: :asc).limit(1).select(:id)
PaperTrail::Version Load (0.9ms) SELECT "versions"."id" FROM "versions" ORDER BY "versions"."created_at" ASC LIMIT $1 [["LIMIT", 1]]
=> [#<PaperTrail::Version:0x00007f4d90935500 id: 10>]
但是当我通过关联尝试同样的事情时, order() 似乎没有生效!
为了说明这一点,这里有一个结果对象,它有 9 个关联版本:
Outcome.last.versions.count
Outcome Load (0.4ms) SELECT "outcomes".* FROM "outcomes" ORDER BY "outcomes"."id" DESC LIMIT $1 [["LIMIT", 1]]
PaperTrail::Version Count (0.4ms) SELECT COUNT(*) FROM "versions" WHERE "versions"."item_id" = $1 AND "versions"."item_type" = $2 [["item_id", 1], ["item_type", "Outcome"]]
=> 9
created_at 排序应该返回不同的版本记录,但他们没有。 :/
Outcome.last.versions.order(created_at: :asc).limit(1).select(:id)
Outcome Load (0.5ms) SELECT "outcomes".* FROM "outcomes" ORDER BY "outcomes"."id" DESC LIMIT $1 [["LIMIT", 1]]
PaperTrail::Version Load (0.5ms) SELECT "versions"."id" FROM "versions" WHERE "versions"."item_id" = $1 AND "versions"."item_type" = $2 ORDER BY "versions"."created_at" ASC, "versions"."id" ASC LIMIT $3 [["item_id", 1], ["item_type", "Outcome"], ["LIMIT", 1]]
=> [#<PaperTrail::Version:0x00007f4d83e6f140 id: 29>]
Outcome.last.versions.order(created_at: :desc).limit(1).select(:id)
Outcome Load (0.4ms) SELECT "outcomes".* FROM "outcomes" ORDER BY "outcomes"."id" DESC LIMIT $1 [["LIMIT", 1]]
PaperTrail::Version Load (0.4ms) SELECT "versions"."id" FROM "versions" WHERE "versions"."item_id" = $1 AND "versions"."item_type" = $2 ORDER BY "versions"."created_at" ASC, "versions"."id" ASC, "versions"."created_at" DESC LIMIT $3 [["item_id", 1], ["item_type", "Outcome"], ["LIMIT", 1]]
=> [#<PaperTrail::Version:0x00007f4d83e66e00 id: 29>]
好吧-当我写下这篇文章时,我意识到可能有一个默认范围......而且确实存在。答案是在查询关联时使用
.unscoped
,例如
Outcome.last.versions.unscoped.order(created_at: :desc).limit(1).select(:id)