Query specified join fetching, but the owner of the fetched association was not present in the select list

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Query specified join fetching, but the owner of the fetched association was not present in the select list

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#1 by (6 votes)

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I have a scenario with the following entities: Treinamento , Curso and Aulas . A Treinamento has a ManyToOne relationship for Curso . And Aula has a ManyToOne relationship to Curso .

I want to make a query that given a given training id returns me the training with your course and with their respective classes filled in the object. I'm doing the query as follows:

Treinamento retorno = null;

    StringBuilder sb = new StringBuilder();
    sb.append("SELECT t FROM Treinamento t ");
    sb.append("INNER JOIN t.idCurso c ");
    sb.append("LEFT JOIN FETCH c.aulas a ");
    sb.append("WHERE t = '"+String.valueOf(treinamento)+"' ");

    retorno = (Treinamento)this.em.createQuery(sb.toString()).getSingleResult();

And I'm getting the error:

Caused by: org.hibernate.QueryException: query specified join fetching, but the owner of the fetched association was not present in the select list [FromElement{explicit,not a collection join,fetch join,fetch non-lazy properties,classAlias=a,role=br.com.empresa.domain.ptreinamentos.Curso.aulas,tableName=Aula,tableAlias=aulas2_,origin=Curso curso1_,columns={curso1_.id ,className=br.com.empresa.domain.ptreinamentos.Aula}}]

The error tells me that the owner of the fetch relationship is not in the select clause. In this case the owner of the relationship would be Curso . What would be the correct way to do this query?

java jpa

asked by anonymous 27.04.2016 / 17:54

1 answer

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score 6 · Accepted Answer

The solution to this problem is that when performing a JOIN FETCH you should start doing FETCH from the first relationship, in my case the query would look like this:

Treinamento retorno = null;

StringBuilder sb = new StringBuilder();
sb.append("SELECT t FROM Treinamento t ");
sb.append("INNER JOIN FETCH t.idCurso c ");
sb.append("LEFT JOIN FETCH c.aulas a ");
sb.append("WHERE t = '"+String.valueOf(treinamento)+"' ");

retorno = (Treinamento)this.em.createQuery(sb.toString()).getSingleResult();