列“users.id”必须出现在GROUP BY子句中或用于聚合函数

关系：

Item belongs to Product Product belongs to User 

物品型号范围：

  scope :search, ->(search_term) { select('products.name, users.*, products.brand, COUNT(products.id)') .joins(:product => :user) .where('users.name = ? OR products.brand = ?', search_term, search_term) .group('products.id') } 

以上结果出现在以下SQL语句中：

 SELECT products.name, users.*, products.brand, COUNT(products.id) FROM "items" INNER JOIN "products" ON "products"."id" = "items"."product_id" INNER JOIN "users" ON "users"."id" = "products"."user_id" WHERE (users.name = 'Atsuete Lipstick' OR products.brand = 'Atsuete Lipstick') GROUP BY products.id 

这里的问题是发生错误：

 ActiveRecord::StatementInvalid: PG::Error: ERROR: column "users.id" must appear in the GROUP BY clause or be used in an aggregate function LINE 1: SELECT products.name, users.*, products.brand, COUNT(product... 

有什么可以解决这个问题？

Answer 1

从错误中可以看出，您应该尝试在GROUP BY子句中包含users.id ：

  .group('products.id, users.id')