Need help with sql query to find things tagged with all specified tags

Question

Let\'s say I have the following tables:

TAGS

id: integer
name: string

POSTS

id: integer
body: text

TAGGINGS

id:

Answer 1

Try this:

Select * From Posts p
   Where Not Exists
       (Select * From tags t
        Where name in 
           ('Cheese', 'Wine', 'Paris', 
             'Frace', 'City', 'Scenic', 'Art')
           And Not Exists
             (Select * From taggings
              Where tag_id = t.Tag_Id
                And post_Id = p.Post_Id))

Explanation: Asking for a list of those Posts that have had every one of a specified set of tags associated with it is equivilent to asking for those posts where there is no tag in that same specified set, that has not been associated with it. i.e., the sql above.