Querry and Projections

[Cristian Colombo]

Hi,

in my project, I have this situation:

@Data
@AllArgumentsConstructor
EntityADTO{
   Long id;
   String name;
   Set<EntityB>;  
}

@Data
@AllArgumentsConstructor
EntityBDTO{
   Long id;
   String name;
}

All class are annotated with Lombok annotations.

What is the correct dsl query, to retrieve only one dto EntityADTO with all populated set of EntityBDTO?
I try the next query, but the results is List of Tuple of projections based by column extracted in defaultEntityAExpression() method and the Set<EntityB> is populated with only one entityB.

sqlQueryFactory.select(defaultEntityAExpression())
      .from(entityA)
      .join(entityB).on(entityB.fk.eq(entityA.id))

public static Expression<EntityADTO> defaultEntityAExpression() {
   //@formatter:off
   return Projections.constructor(EntityADTO.class,
         entityA.id,
         entityA.name,
         Projections.list(defaultEntityBexpression()));
   //@formatter:on
}

public static Expression<EntityBDTO> defaultEntityBexpression() {
   //@formatter:off
   return Projections.constructor(EntityBDTO.class,
         entityB.id,
         entityB.name);
         
   //@formatter:on
}

I'm using the querydsl sql module (no JPA, no JDO etc.). I would like to get the same results that I would get by using hibernate 

Thanks in advance,

Cristian

[Liam Coughlin]

Hi -- To my knowledge you can't exactly, however you can do something like:

Map<EntityADTO, List<EntityBDTO>> result = sqlQueryFactory.select(defaultEntityAExpression())
        .from(entityA)
        .join(entityB).on(entityB.fk.eq(entityA.id))
        .transform(GroupBy.groupBy(entityA)).as(list(entityB));

I know that's not exactly what you're looking for but if you poke at it, you can probably come up with a ResultTransformer that does what you want.  If you do, please post it back to the group, you're probably not the only one interested.