在Rails3 Active Record查询上使用acts_as_taggable_on？

Question

If I want to select a group of records from a database using a SQL query and further qualify it by what tag(s) are set on a record - is there an easy way to do this?

eg something conceptually like Select * from Corps where date_added > '2010-01-01' and tag like "legal"

Obviously this isn't correct since the tag data isn't kept in the table, but you get the idea.

Rails3 has a new syntax for Active Record queries. Can I select a group of records using the AREL AR syntax, then apply the tag find operation to that?

Answer 1

Yes, with the tagged_with() method.

Example using your sample SQL query:

@corps = Corp.where('date_added > 2010-01-01').tagged_with('legal')

You can also put an array of tags into tagged_with ( tagged_with(['legal', 'foo']) ).