弃用警告：隐式连接引用。 Rails 不想成为包含的 SQL 解析器

Question

我正在将旧应用程序从 rails3 升级到 rails 4。目前在 rails 4.0

在运行 rspec 时，我有很多这样的弃用警告：

  Currently, Active Record recognizes the table in the string, and 
knows to JOIN the comments table to the query, rather than loading 
comments in a separate query. However, doing this without writing a 
full-blown SQL parser is inherently flawed. Since we don't want to 
write an SQL parser, we are removing this functionality. From now on, 
you must explicitly tell Active Record when you are referencing a 
table from a string:

Post.includes(:comments).where("comments.title = 
'foo'").references(:comments)

If you don't rely on implicit join references you can disable the 
feature entirely by setting 
`config.active_record.disable_implicit_join_references = true`. 

 DEPRECATION WARNING: It looks like you are eager loading table(s) 
 (one of: product_masters, product_master_names) that are referenced 
 in a string SQL snippet. For example: 

Post.includes(:comments).where("comments.title = 'foo'")

这是导致错误的行

def find_product_master
    masters = ProductMaster.includes(:product_master_names).where("gcc = 1 and crossed_product_master_id is null and product_masters.supplier_id is null && (product_masters.slug = :name or product_masters.slug = :clean_name or product_master_names.slug = :name or product_master_names.slug = :clean_name) and product_masters.color = :color and (product_subfamily_id = :subfamily_id or second_product_subfamily_id = :subfamily_id)", name: line.file_name.parameterize, clean_name: line.file_name.parameterize.gsub("chateau","").parameterize, color: line.file_color, subfamily_id: line.product_subfamily_id)
    masters.size == 1 ? line.update_column(:product_master_id, masters.first.id) : line.update_column(:status, "product_master_missing")
end

我试过了，就像警告中描述的那样

 def find_product_master
    masters = ProductMaster.includes(:product_master_names).where("gcc = 1 and crossed_product_master_id is null and product_masters.supplier_id is null && (product_masters.slug = :name or product_masters.slug = :clean_name or product_master_names.slug = :name or product_master_names.slug = :clean_name) and product_masters.color = :color and (product_subfamily_id = :subfamily_id or second_product_subfamily_id = :subfamily_id)".references(:product_master_names), name: line.file_name.parameterize, clean_name: line.file_name.parameterize.gsub("chateau","").parameterize, color: line.file_color, subfamily_id: line.product_subfamily_id)
    masters.size == 1 ? line.update_column(:product_master_id, masters.first.id) : line.update_column(:status, "product_master_missing")
 end

然后我收到一个错误

 NoMethodError:
    undefined method `references' for #<String:0x00000010f2c730>

Answer 1

只需在include 调用后面链接references，而不是在where 的参数之一上调用reference：

masters = ProductMaster
  .includes(:product_master_names)
  .references(:product_master_names)
  .where(
    # ...
  )