How to Query Associations using Dictionary?

[Silber_Felix]

I have the following example:

ObjectManager.Find<TChildEntity>
  .Select(TProjections.Count(csId))
  .Where(Linq['ParentEntity'] = SomeId).UniqueValue.

which creates the following SQL:

Select count('id')
  from child_entity
 where parent_entity_id = 1

This works fine.

But I'd like to use our dictionary for this.

Trying to fetch the Child like this:

ObjectManager.Find<TChildEntity>
  .Select(TProjections.Count(csId))
  .Where(EntDic.ChildEntity.ParentEntity.Id = SomeId).UniqueValue.

will create the following SQL:

Select count('a.id')
  from child_entity a
  left join parent_entity b on a.parent_entity_id = b.id
 where b.id = 1

How to use the Dictionary, getting the first SQL-Statement?

[wlandgraf (Wagner Landgraf)]

Actually your first query works "by accident" and is not officially supported by Aurelius. Thus there is no alternative for it using dictionary.

[Silber_Felix]

Ok, can you tell me, what would be the supported way do fetch this?

[wlandgraf (Wagner Landgraf)]

You can use an SQL expression to query directly by the database column name, as described here:

FindColumn by Column-Name

As an ORM, Aurelius abstracts the underlying database and allows the user to work with the objects. So it doesn't make much sense to use the "low-level" column names as if they were properties of the object. Conceptually, you are querying objects, not tables. But you can achieve what you want this way: Find<TEntityCustFld> .Where(Linq.Sql<Integer>('A.MainId = ?'), someValue) .UniqueResult;

For example:

ObjectManager.Find<TChildEntity>
  .Select(TProjections.Count(csId))
  .Where(Linq.Sql<Integer>('A.parent_id = ?'), someValue)