Adding custom HQL to the query

Custom HQL can be added to the query by making use of the HqlQueryValue or the CustomTypeSafeValue. The CustomTypeSafeValue just wraps a HqlQueryValue.

This is useful when working with a library to generate parts of the query. In any other case it is probably better to create a dedicated TypeSafeValue.

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Example group by custom hql:

Building building = query.from(Building.class);

query.select(building.getConstructionDate());
query.setHqlAlias(building, "b");
query.groupBy(new CustomTypeSafeValue<Date>(query, 
    Date.class, "b.constructionDate"));

=> "select b.constructionDate 
    from Building b 
    group by b.constructionDate"

Example restricting by a custom hql restriction:

House house = query.from(House.class);
query.where(new HqlQueryValueImpl("hobj1.floors > ?", 10));

=> "from House hobj1 where hobj1.floors > ?" [10]