foreign-keys

I have the two tables : table A with id as primary key table B with id as primary key and foreign key Explanation on short: I need to have in table B a primary key that also to be a foreign key that points to table A 's primary key. Can anybody explain me how to map this by annotations in Doctrine 2? Note: I tried it By this : class A { /** * @var bigint $id * * @Column(name="id", type="bigint", nullable=false) * @Id * @GeneratedValue(strategy="IDENTITY") */ private $a_id; ... and B table: class B { /** * @var bigint $id * @Id * @OneToOne(targetEntity="A", fetch="LAZY") * @JoinColumn(name="id"

Getting this error when I try to instantiate the ConsumerAdvice class. Foreign key associated with column 'tbConsumerAdvice.ConsumerAdviceCategory_ID' could not find table 'tbConsumerAdviceCategories' with which to generate a foreign key to target column 'ID_ConsumerAdviceCategories' class ConsumerAdviceCategory(Base): __tablename__ = 'tbConsumerAdviceCategories' __table_args__ = {'schema':'dbo'} ID_ConsumerAdviceCategories = Column(INTEGER, Sequence('idcac'),\ primary_key=True) Name = Column(VARCHAR(50), nullable=False) def __init__(self,Name): self.Name = Name def __repr__(self): return "<

The issue has been my weekend nightmare... I have a table where AddOrUpdate is not working correctly, it keeps adding but never updating. All I want to do is when I add a new entity to the table using AddOrUpdate I want it to check the AppointmentId and CompletionCodeId columns and if they match than update, otherwise add. Table structure: CREATE TABLE [dbo].[AppointmentCodes] ( [Id] INT IDENTITY (1, 1) NOT NULL, [AppointmentId] INT NOT NULL, [Quantity] INT NOT NULL, [CompletionCodeId] INT NOT NULL, CONSTRAINT [PK_AppointmentCodes] PRIMARY KEY CLUSTERED ([Id] ASC, [AppointmentId] ASC)); ^^ Not

I have an object called "Customer" which will be used in the other tables as foreign keys. The problem is that I want to know if a "Customer" can be deleted (ie, it is not being referenced in any other tables). Is this possible with Nhibernate? Jaguar What you are asking is to find the existence of the Customer PK value in the referenced tables FK column. There are many ways you can go about this: as kgiannakakis noted, try to do the delete and if an exception is thrown rollback. Effective but ugly and not useful. This also requires that you have set a CASCADE="RESTRICT" in your database. This

Using code-first Entity Framework and .NET 4, I'm trying to create a one-to-many relationship between parents to children: public class Parent { [Key] public int ParentId { get; set; } [Required] public string ParentName { get; set; } public IEnumerable<Child> Children { get; set; } } public class Child { [Key] public int ChildId { get; set; } [ForeignKey] public int ParentId { get; set; } [Required] public string ChildName { get; set; } } As pointed out here , in order for foreign key relationship to carry into the database, the actual objects must be linked, not just their IDs. The normal

There is this field in a table: room_id INT NOT NULL CONSTRAINT room_id_ref_room REFERENCES room I have three 2 tables for two kinds of rooms: standard_room and family_room How to do something like this: room_id INT NOT NULL CONSTRAINT room_id_ref_room REFERENCES standard_room or family_room I mean, room_id should reference either standard_room or family_room . Is it possible to do so? Here is the pattern I've been using. CREATE TABLE room ( room_id serial primary key, room_type VARCHAR not null, CHECK CONSTRAINT room_type in ("standard_room","family_room"), UNIQUE (room_id, room_type) );

I'm dynamically storing information in the database depending on the request: // table, id and column are provided by the request table_obj = getattr(models, table) record = table_obj.objects.get(pk=id) setattr(record, column, request.POST['value']) The problem is that request.POST['value'] sometimes contains a foreign record's primary key (i.e. an integer) whereas Django expects the column's value to be an object of type ForeignModel: Cannot assign "u'122'": "ModelA.b" must be a "ModelB" instance. Now, is there an elegant way to dynamically check whether b is a column containing foreign keys