Hello,

I am using version 3.1 Final dated 2/22/2012 in adapter mode.

Based on this response by daelmo, I am trying to get his example code to work to allow me to delete multiple entities based on a key in a generic manner.

http://www.llblgen.com/tinyforum/Messages.aspx?ThreadID=17841

My code:

public void Delete<T>(object key) where T : class, new()
        {
            var entity = new T();

            // get pk
            var pkField = (EntityField2)((IEntity2)entity).GetPrimaryKey();

            // create filter
            var filter = new PredicateExpression();
            filter.Add(pkField == key);

            // fetch
            var coll = ((IEntity2)entity).GetEntityFactory().CreateEntityCollection();
            coll.GetMulti(pkField == key);

            this.Adapter.DeleteEntityCollection(coll);

            return; 
        }

        public static IEntityField2 GetPrimaryKey(this IEntity2 entity)
        {
            return entity.PrimaryKeyFields[0];
        }

The issue is that GetMulti is not part of IEntityCollection2. How do I fill the collection and then delete the entities? Is there an easier way?

Thank you.

Hi there,

For adapter is slightly different, because the persistence logic in adapter is outside the entity. Also you don't need to fetch the entity, you can direct call DeleteEntitiesDirectly. Try this:

public void Delete<T>(object key) where T : IEntity2, new()
{
    var entity = new T();

    // get pk
    var pkField = (EntityField2) GetPrimaryKey((IEntity2)entity);

    // create filter
    var filter = new RelationPredicateBucket();
    filter.PredicateExpression.Add(pkField == key);

    using (var adapter = new DataAccessAdapter())
    {
        adapter.DeleteEntitiesDirectly(typeof(T), filter);
    }

    return;
}

public static EntityField2 GetPrimaryKey(IEntity2 entity)
{
    return (EntityField2) entity.PrimaryKeyFields[0];
}

Usage:

Delete<CustomerEntity>("ALFI");

Note that this code only works if the entity has just 1 PK field. If the entity has a composite key, then you will delete multiple rows, not just one.

Worked perfectly. Thank you!