I'm performing a Query to my DB in JPA. The Query "queries" 4 tables, and the result aggregates columns from that different tables.
My Query is something like:
Query query = em.createQuery("SELECT o.A, o.B, o.C, e.D, c.E FROM Table1 o,
Table2 i, Table3 e, Table4 c WHERE o.X = i.X AND i.Y = e.Y AND i.Z = c.Z");
How can I get the query result and extract the different fields?
I created a class (MyObject) that represents each item of the result list, and I want to convert the query.getResultList()
into a List< MyObject>
.
How can I do it?
This kind of query returns a List<Object[]>
. So you just need a loop to convert each array into an instance of your class:
List<Object[]> rows = query.getResultList();
List<MyObject> result = new ArrayList<>(rows.size());
for (Object[] row : rows) {
result.add(new MyObject((String) row[0],
(Long) row[1],
...));
}