Sql 使查询工作，但希望改为ActiveRelation

一个

项目

有

遗留用户

和

组用户

<代码>组用户必须通过

组

才能获得

用户

。我想构建一个

项目。用户

将这些查询组合为arel

以下是

项目

：

class Project < ActiveRecord::Base
  has_many    :project_accesses

  has_many    :groups,       through: :project_accesses, source: :group
  has_many    :legacy_users, through: :project_accesses, source: :user
  has_many    :group_users,  through: :groups, source: :users
end

下面是用于

项目的sql。查找（1）。对用户进行分组

：

SELECT "users".* FROM "users" INNER JOIN "project_accesses" ON "users"."id" =
"project_accesses"."user_id" WHERE "users"."deleted_at" IS NULL AND 
"project_accesses"."deleted_at" IS NULL AND "project_accesses"."project_id" = 1

SELECT "users".* FROM "users" INNER JOIN "group_memberships" ON "users"."id" =
"group_memberships"."user_id" INNER JOIN "groups" ON "group_memberships"."group_id" = 
"groups"."id" INNER JOIN "project_accesses" ON "groups"."id" = 
"project_accesses"."group_id" WHERE "users"."deleted_at" IS NULL AND 
"group_memberships"."deleted_at" IS NULL AND "groups"."deleted_at" IS NULL AND 
"project_accesses"."deleted_at" IS NULL AND "project_accesses"."project_id" = 1

SELECT "users".* FROM "users" INNER JOIN "group_memberships" ON "users"."id" = 
"group_memberships"."user_id" INNER JOIN "groups" ON "group_memberships"."group_id" = 
"groups"."id" INNER JOIN "project_accesses" ON ("groups"."id" = 
"project_accesses"."group_id" OR "users"."id" = "project_accesses"."user_id") WHERE 
"users"."deleted_at" IS NULL AND "group_memberships"."deleted_at" IS NULL AND 
"groups"."deleted_at" IS NULL AND "project_accesses"."deleted_at" IS NULL AND 
"project_accesses"."project_id" = 1

只需在

内部连接“project\u access”

条件上添加

或

，我就可以得到我想要的<代码>项目.查找（1）.用户：

SELECT "users".* FROM "users" INNER JOIN "project_accesses" ON "users"."id" =
"project_accesses"."user_id" WHERE "users"."deleted_at" IS NULL AND 
"project_accesses"."deleted_at" IS NULL AND "project_accesses"."project_id" = 1

SELECT "users".* FROM "users" INNER JOIN "group_memberships" ON "users"."id" =
"group_memberships"."user_id" INNER JOIN "groups" ON "group_memberships"."group_id" = 
"groups"."id" INNER JOIN "project_accesses" ON "groups"."id" = 
"project_accesses"."group_id" WHERE "users"."deleted_at" IS NULL AND 
"group_memberships"."deleted_at" IS NULL AND "groups"."deleted_at" IS NULL AND 
"project_accesses"."deleted_at" IS NULL AND "project_accesses"."project_id" = 1

SELECT "users".* FROM "users" INNER JOIN "group_memberships" ON "users"."id" = 
"group_memberships"."user_id" INNER JOIN "groups" ON "group_memberships"."group_id" = 
"groups"."id" INNER JOIN "project_accesses" ON ("groups"."id" = 
"project_accesses"."group_id" OR "users"."id" = "project_accesses"."user_id") WHERE 
"users"."deleted_at" IS NULL AND "group_memberships"."deleted_at" IS NULL AND 
"groups"."deleted_at" IS NULL AND "project_accesses"."deleted_at" IS NULL AND 
"project_accesses"."project_id" = 1

基本上，我只是改变了，让查询做我想要的：

INNER JOIN "project_accesses" ON ("groups"."id" = "project_accesses"."group_id" OR "users"."id" = "project_accesses"."user_id")

现在的问题是，这只是一个字符串，通过sql传递到

find\u，我不知道如何使它成为一个正确的Arel

提前感谢您的帮助
 您应该能够使用ARel的
joins
方法手动构建您的join，并且仍然可以恢复一个活动关系

我越来越近了：

User.joins(:groups).joins("inner join project_accesses on (groups.id = 
project_accesses.group_id or users.id = project_accesses.user_id)").
where(project_accesses: {project_id:1}).merge(Group.scoped).
merge(GroupMembership.scoped).merge(ProjectAccess.scoped).uniq

有没有办法用Arel来写这部分

joins("inner join project_accesses on (groups.id = 
project_accesses.group_id or users.id = project_accesses.user_id)")

此外，是否有一种方法可以自动包含所有关联模型的默认范围，以避免：

.merge(Group.scoped).merge(GroupMembership.scoped).merge(ProjectAccess.scoped)