many-to-many

问题 I have 2 objects, with many to many relationships. Here's my code: + (NSSet *)activitiesSetForMember:(Members *)member inManagedObjectContext:(NSManagedObjectContext *)context{ NSSet *activitiesSet = nil; NSFetchRequest *request = [[NSFetchRequest alloc] init]; request.entity = [NSEntityDescription entityForName:@"CompanyActivity" inManagedObjectContext:context]; request.predicate = [NSPredicate predicateWithFormat:@"hasMembers contains %@", member]; NSError *error = nil; activitiesSet = [

问题 I have the following models: RECIPE, TAG and TAGGING (join table) recipe.rb has_many :taggings has_many :tags, through: :taggings accepts_nested_attributes_for :taggings tag.rb has_many :taggings has_many :recipes, through: :taggings scope :diet, -> { where(type_id: 1).to_a } scope :category, -> { where(type_id: 2).to_a } scope :festivity, -> { where(type_id: 3).to_a } scope :daily, -> { where(type_id: 4).to_a } Everything normal so far. But, in my TAGS table I have a field called "type_id"

问题 I have the current table setup for a many to many association between "words" and "phrases": association_table_wp = Table('words_phras', Base.metadata, autoload=True, extend_existing=True) class Phrase(Base): __tablename__ = 'phrases' __table_args__ = {'autoload': True} def __init__(self, phrase, explanation=None, active=False): self.phrase = phrase self.explanation = explanation self.active = active class Word(Base): __tablename__ = 'words' __table_args__ = {'autoload': True} def __init__

问题 I have a many-to-many relationship which looks like this: The primary key is combination of three columns and I'm using eclipselink. I created these classes to be able to insert in the join-table : @Entity @Table(name = "definition_property") @NamedQueries({ @NamedQuery(name = "DefinitionProperty.findAll", query = "SELECT d FROM DefinitionProperty d")}) public class DefinitionProperty extends AbstractEntity{ private static final long serialVersionUID = 1L; @EmbeddedId protected

问题 I have a many-to-many relationship between two entities; Item and Tag. I'm trying to create a predicate to take the selectedItem and return a ranking of items based on how many similar tags they have. So far I've tried: NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SUBQUERY(itemToTag, $item, $item in %@).@count > 0", selectedItem.itemToTag]; Any other iterations that have failed. It currently only returns the selectedItem in the list. I've found little on Subquery. Is there a

问题 So I've this relations defined in my entities: class Producto { /** * @ORM\ManyToMany(targetEntity="AppBundle\Entity\Norma", inversedBy="normasProducto", cascade={"persist"}) * @ORM\JoinTable(name="nomencladores.norma_producto", schema="nomencladores", * joinColumns={@ORM\JoinColumn(name="producto_id", referencedColumnName="id")}, * inverseJoinColumns={@ORM\JoinColumn(name="norma_id", referencedColumnName="id")} * ) */ protected $productoNormas; } class Norma { /** * @ORM\ManyToMany

问题 Good morning, I have the following schemas in mind which the login as describe below image. Normally, the association table would contain the Key of table Position, Division, and Qualification. I am not sure whether this schema is well form or not.If it does could you please guide me how to represent it in Nhibernate XML schemas and PoCo class? Best regards, Veasna 回答1: Your schema, your ideas, are prove of concept: do not use many-to-many mapping. Chapter 24. Best Practices Don't use exotic

问题 I am very new to Nhibernate. I would like to develop an application in asp.net by using NHibernate as mapping database tools. I have following tables schemas: CREATE TABLE [dbo].[tblTeam]( [TeamID] [int] IDENTITY(1,1) NOT NULL, [TeamName] [varchar](100) NOT NULL ) CREATE TABLE [dbo].[tblEmployee]( [EmployeeID] [int] IDENTITY(1,1) NOT NULL, [EmployeeName] [varchar](100) NOT NULL ) CREATE TABLE [dbo].[tblTeamEmployee]( [TeamID] [int] NOT NULL, [EmployeeID] [int] NOT NULL ) And here is

问题 These two questions answered many of my questions, but I am still struggling to think about in real scenario! Taking an example from the references. Assume I have one Order and Multiple Items associated with it. Now assume One Item can have one Returns but one Returns can have multiple Items. What I understood is, Order to Items will be One to Many Relation . Since I need to get Order of an Item, I will create column 'order_fk' in Item table to get it. //Order entity @OneToMany @JoinColumn

问题 I have a many to many relationship between Portfolio and PortfolioTags A portfolio Item can have many PortfolioTags I am looking at the best way of saving tags to a portfolio item. My Nhibnerate maps are like so: public class PortfolioMap : ClassMap<Portfolio> { public PortfolioMap() { Table("Portfolio"); LazyLoad(); Id(x => x.Id).GeneratedBy.Identity().Column("Id"); Map(x => x.AliasTitle).Column("AliasTitle").Not.Nullable(); Map(x => x.MetaDescription).Column("MetaDescription").Not.Nullable(