Criteria API and left join on a dictionary/map
I have the following classes:
public class Item
{
public int Id { get; set; }
public IDictionary<int, ItemLocal> { get; protected set; }
public ICollection<stri开发者_运维问答ng> Tags { get; set; }
public int DefaultLanguageId { get; set; }
public DateTime Start { get; set; }
}
public class ItemLocal
{
public virtual Item Parent { get; set; }
public virtual int LanguageId { get; set; }
public string Title { get; set; }
public string Description { get; set; }
}
These map to the tables Item, ItemTag and ItemLocal. I want to make the following query via the criteria api:
select
i.Id,
i.Start,
l.Title
from
Item i
left join ItemLocal l on i.Id = l.ParentId and i.DefaultLangaugeId = l.LanguageId
order by
l.Title,
i.Id
But I dont know how to perform the left join with the nhibernate criteria api. Especially with the usage of the default language selection.
Any help is very appreciated.
I have found a solution:
Session
.CreateCriteria<Item>("i")
.CreateCriteria("Localization", "l", NHibernate.SqlCommand.JoinType.LeftOuterJoin)
.Add(Restrictions.Disjunction()
.Add(Restrictions.EqProperty("i.DefaultLanguageId", "l.LanguageId"))
.Add(Restrictions.IsNull("l.LanguageId"))
)
.AddOrder(Order.Asc("l.Title"))
.AddOrder(Order.Asc("w.Id"));
This seems to work but results in a query with a workaround WHERE clause. Would rather see that it could render a SQL query where the restrictions defined in the disjunction could be part of the OUTER LEFT JOIN ... ON ... statement.
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