Set Mysql-Parameter group_concat_max_len

Question

I'm using JPA / EclipseLink for Database-Access. Within my MySQL-Database I need to seet the Parameter group_concat_max_len to a larger number. Can I do this with JPA?

I tried it with the following statement:

Query query = em.createNativeQuery("SET  group_concat_max_len = 10240;");

But this throws an java.lang.IllegalStateException: Invalid call on a query that does not return result sets.

Can somebody help?

Thanks Bernhard

Maybe this can help https://stackoverflow.com/questions/276927/can-i-concatenate-multiple-mysql-rows-into-one-field/276949#276949 — Rodrigo Almeida Bezerra, Jan 08 '20 at 17:11

score 0 · Answer 1 · answered Sep 23 '13 at 17:42

0

Line of code that causes error is missing from the question. Following does not throw described exception:

Query query = em.createNativeQuery("SET  group_concat_max_len = 10240;");

But if created instance of Query is used as follows, then exception will be thrown:

query.getResultList();
//or 
query.getSingleResult();

Solution is to call executeUpdate method instead of ones above:

query.executeUpdate();

answered Sep 23 '13 at 17:42

Mikko Maunu

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Hi, thanks for help, now after embedding the executeUpdate in a transaction, it worked. – stoi Sep 23 '13 at 19:25

Set Mysql-Parameter group_concat_max_len

1 Answers1