how to find entries with no tags using acts-as-taggable-on?
What's the Right Way(tm) to find the entries that have no tags?
I tried using Entry.tagged开发者_如何学C_with(nil)
but it just returns an empty hash.
I need it so I can list the entries I still need to tag.
Thanks.
The following seems to work for me:
Entry.includes("taggings").where("taggings.id is null")
This should support chaining as well. For example, the following should work:
Entry.includes("taggings").where("taggings.id is null").where(foo: "bar")
Here is my solution to find the tagged and untagged photos.
scope :with_taggings, where('id in (select taggable_id from taggings where taggable_type = ’Photo‘ and context = ’bibs‘)')
scope :without_taggings, where('id not in (select taggable_id from taggings where taggable_type = ’Photo‘ and context = ’bibs‘)')
But it works for the Photo model, but can not be chained with other scopes.
I realize this is ancient but I just came on a similar need today. I just did it with a simple multiple-query scope:
scope :untagged, lambda {
# first build a scope for the records of this type that *are* tagged
tagged_scope = Tagging.where(:taggable_type => base_class.to_s)
# only fetching the taggable ids
tagged_scope = tagged_scope.select('DISTINCT taggable_id')
# and use it to retrieve the set of ids you *don't* want
tagged_ids = connection.select_values(tagged_scope.to_sql)
# then query for the rest of the records, excluding what you've found
where arel_table[:id].not_in(tagged_ids)
}
It may not be efficient for huge datasets but it suits my purposes.
Without knowing the internals of acts-as-taggable-on I can't think of a neat way that doesn't involve looping queries or raw SQL. This is readable:
need_to_tag = []
Entry.all.each do |e|
need_to_tag << e if e.tag_list.blank?
end
need_to_tag then holds any untagged Entries.
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