many-to-many

I'm trying to do a simple Post/Tags relation in rails 3. Everything working fine except when I want to query the Posts which are related to several tags. Basically I'd like to do this kind of thing : Post.joins(:tags).where('tags.name ILIKE ?', var) But instead of having just one var, I'd like to use an array. I tried : Post.joins(:tags).where('tags.name IN (?)', names_array) But unfortunately it does a simple LIKE (not ILIKE) and works like a OR condition which sounds perfectly logical. I also found another solution by using find_by_sql in this post http://snippets.dzone.com/posts/show/32 But

I'm trying to build a many to many relationship using the entity framework and fluent API, but I'm stuck trying to allow duplicate entries. Here is what I have: public class Pizza { public int PizzaId { get; set; } public virtual ICollection<Topping> Toppings { get; set; } } public class Topping { public int ToppingId { get; set; } } Any pizza should be able to have multiple toppings. Any topping can be applied to multiple pizzas. So in OnModelCreating() I call: modelBuilder.Entity<Pizza>() .HasMany(p => p.Toppings) .WithMany() .Map(m => m.ToTable("ToppingsForPizza")); That give me a nice many

I am trying to build simple many-to-many relationship using Flask-Sqlalchemy for Postgresql Database: from app import db from sqlalchemy.dialects.postgresql import UUID authors_books = db.Table( 'authors_books', db.Column('id', UUID(as_uuid=True), primary_key=True), db.Column('author_id', UUID(as_uuid=True), db.ForeignKey('authors.id')), db.Column('book_id', UUID(as_uuid=True), db.ForeignKey('books.id')), ) class Author(db.Model): __tablename__ = 'authors' # Fields id = db.Column(UUID(as_uuid=True), primary_key=True) first_name = db.Column(db.String) last_name = db.Column(db.String) #

Let's say we have two tables with a many-to-many relationship: public class Left{ /**/ } public class Right{ /**/ } public class LeftRight{ /**/ } is the following sufficient to unhook these records (ignore the possibility of more than one relationship or no relationship defined)? public void Unhook(Left left, Right right){ var relation = from x in Left.LeftRights where x.Right == right; left.LeftRrights.Remove(relation.First()); Db.SubmitChanges(); } Or do I have to do it on both parts? What's required here? Here is a 'little' extension method I wrote to simplify this problem: public static

(I don't think I have titled this question correctly - but I don't know how to describe it) Here is what I am trying to do: Let's say I have a Person table that has a PersonID field. And let's say that a Person can belong to many Groups. So there is a Group table with a GroupID field and a GroupMembership table that is a many-to-many join between the two tables and the GroupMembership table has a PersonID field and a GroupID field. So far, it is a simple many to many join. Given a list of GroupIDs I would like to be able to write a query that returns all of the people that are in ALL of those

I've been tokenizing an extremely large corpus. Each Unigram can occur in multiple Comments multiple times. I'm storing the Comment.ids in a list that is attached to the Unigram in the database every 250K newly counted unigrams or so. What I'm wondering is if there is a way to extend the comment id list--or a similar data structure--without querying and loading the existing list of comments tied to the Unigram (it can number in the the thousands). Or is there no way around the slow IO? Here is my model code: comments = db.Table('ngrams', db.Column('unigram_id', db.String, db.ForeignKey(