How to use multiple primary keys

Question

I created database, for my android app, witch has 16 tables. I want to use ORMlite mapping. The problem is that I didn\'t find examples where you have composite id(Multiple

Answer 1

ServiceStack's OrmLite by design doesn't support multiple composite primary keys. In order for your same POCOs to be useful outside of a db (e.g. NoSQL datastores, cache providers, etc) OrmLite expects a single primary key on each type, which my default is the Id property (overridable with ModelConfig class or [PrimaryKey], [Alias] attributes).

Work arounds to overcome this limitation include creating a single unique Id but include a unique constraint on the composite primary keys, e.g:

[CompositeIndex("CompositePkId1","CompositePkId2", Unique = true)] 
public class Poco 
{
    [AutoIncrement]
    public int Id { get; set; }
    public int CompositePkId1 { get; set; }
    public int CompositePkId2 { get; set; }
}

Or creating a pseudo column that contains combination of all primary keys, e.g:

public class Poco 
{
    public string Id { get { return CompositePkId1 + ":" + CompositePkId2; } }
    public int CompositePkId1 { get; set; }
    public int CompositePkId2 { get; set; }
}