ruby-on-rails - 查找具有关系记录的记录失败:PG::UndefinedTable: ERROR: missing FROM-clause entry for table

Question

我有模型 Activity，它 has_one ComputedActivity。我想找到所有已完成处理的事件，这意味着它们在数据库中有一个计算事件。

我写了这个查询

Activity.joins(:computed_activity).where.not(computed_activity: {id: nil})

这给了我错误

ActiveRecord::StatementInvalid (PG::UndefinedTable: ERROR:  missing FROM-clause entry for table "computed_activity")
LINE 1: ...tivities"."activity_id" = "activities"."id" WHERE "computed_...
                                                             ^
: SELECT  "activities".* FROM "activities" INNER JOIN "computed_activities" ON "computed_activities"."activity_id" = "activities"."id" WHERE "computed_activity"."id" IS NOT NULL LIMIT $1

是什么导致失败，我该如何解决？

Answer 1

ActiveRecord::StatementInvalid (PG::UndefinedTable: ERROR: missing FROM-clause entry for table "computed_activity") LINE 1: ...tivities"."activity_id" = "activities"."id" WHERE "computed_...

您应该在 where 子句中包含表名，而不是模型名。所以只要改变

Activity.joins(:computed_activity).where.not(computed_activity: {id: nil})

到

Activity.joins(:computed_activity).where.not(computed_activities: {id: nil})