ruby-on-rails - 嵌套联接表上的Rails 4 where子句

当前我有此查询：

Mother.joins(camp: [{ sub_center: [{ health_center: :block }] }])

它通过mother、block和camp表将sub_center表连接到health_center表（我知道这需要很多东西）。我想做这样的事情：

Mother.joins(camp: [{ sub_center: [{ health_center: :block }] }]).where(sub_center_id: 1)

但是，我得到sub_center_id是一个未定义的列PG::UndefinedColumn: ERROR: column mothers.sub_center_id does not exist
如何让它查询camp.sub_center_id而不是mother.sub_center_id？换句话说，如何在嵌套联接表上执行where子句？
下面是给定表的架构：

create_table "mothers", force: :cascade do |t|
    t.integer  "camp_id"
    t.integer  "eligible_couple_id"
    t.string   "pcts_id"
    t.integer  "thumb_id"
    t.string   "survey_id"
    t.string   "necklace_id"
    t.integer  "necklace_replacement_number", default: 0
    t.boolean  "facility_referral_true",      default: false
    t.float    "weight_at_las_pnc"
    t.integer  "created_by"
    t.integer  "updated_by"
    t.datetime "created_at",                                  null: false
    t.datetime "updated_at",                                  null: false
    t.string   "reg_id"
    t.string   "nfc_data"
    t.datetime "date_of_registration"
    t.integer  "status",                      default: 1,     null: false
    t.datetime "deleted_at"
    t.datetime "completed_at"
  end

create_table "camps", force: :cascade do |t|
    t.string   "english_name"
    t.string   "local_name"
    t.float    "latitude"
    t.float    "longitude"
    t.datetime "created_at"
    t.datetime "updated_at"
    t.integer  "created_by"
    t.integer  "updated_by"
    t.integer  "sub_center_id"
    t.integer  "week_of_the_month"
    t.integer  "status",            default: 1
    t.integer  "day"
    t.datetime "deleted_at"
  end

  create_table "health_centers", force: :cascade do |t|
    t.integer  "block_id"
    t.string   "english_name"
    t.string   "local_name"
    t.boolean  "phc_true",         default: false
    t.boolean  "ipd_true",         default: false
    t.boolean  "fru_true",         default: false
    t.boolean  "always_open_true", default: false
    t.string   "phone_number"
    t.integer  "created_by"
    t.integer  "updated_by"
    t.datetime "created_at",                       null: false
    t.datetime "updated_at",                       null: false
    t.integer  "status",           default: 1
    t.datetime "deleted_at"
  end

create_table "sub_centers", force: :cascade do |t|
    t.integer  "health_center_id"
    t.string   "english_name"
    t.string   "local_name"
    t.boolean  "phc_true",         default: false
    t.boolean  "ipd_true",         default: false
    t.boolean  "fru_true",         default: false
    t.boolean  "always_open_true", default: false
    t.string   "phone_number"
    t.float    "latitude"
    t.float    "longitude"
    t.integer  "created_by"
    t.integer  "updated_by"
    t.datetime "created_at",                       null: false
    t.datetime "updated_at",                       null: false
    t.integer  "status",           default: 1
    t.datetime "deleted_at"
  end

  create_table "blocks", force: :cascade do |t|
    t.string   "english_name"
    t.string   "local_name"
    t.datetime "created_at"
    t.datetime "updated_at"
    t.integer  "created_by"
    t.integer  "updated_by"
    t.integer  "status",       default: 1
    t.datetime "deleted_at"
  end

最佳答案

您始终可以使用string方法来引用列，而不是符号列。

Mother.
  joins(camp: { sub_center: { health_center: :block } }).
  where('camps.sub_center_id = ?', 1)

或者用符号法

Mother.
  joins(camp: { sub_center: { health_center: :block } }).
  where(camps: { sub_center_id: 1 } )

关于ruby-on-rails - 嵌套联接表上的Rails 4 where子句，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/44659998/