The fastest way to check if some records in a database table using hibernate

Question

I have java app that uses hibernate orm to work with db? so what is fastest way to check presense of record(mapped to a hibernate object) in db

Use your dao to select from the database? I don't really understand the question. — Tim Pote, Apr 26 '12 at 16:13
I do not want select all fields of an object and looking for a simple way of check provided by api — user590444, Apr 26 '12 at 16:17

dogbane · Answer 1 · 2012-04-26T16:34:02.800

5

Use entityManager.find.

Example from the docs:

long catId = 1234L;
em.find( Cat.class, new Long(catId) );

Alternatively, count the records:

Integer count = (Integer) session.createQuery("select count(*) from Cats c where c.id = :catId")
                          .setLong("catId", 1234L)
                          .uniqueResult();
boolean exists = count > 0;

edited Apr 26 '12 at 16:34

answered Apr 26 '12 at 16:19

dogbane

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I do not want select all fields of an object and looking for a simple way of check provided by api – user590444 Apr 26 '12 at 16:21
@user590444 "simple way of check provided by api" what?? – maksimov Apr 26 '12 at 16:28
if you don't want to select all fields, then select one field - what's the problem? you MUST select at least something from the database to see if a particular record is there - something to return for your WHERE clause. – maksimov Apr 26 '12 at 16:31
2

Alternatively, count the records. See my update. – dogbane Apr 26 '12 at 16:34
DetachedCriteria favorites = DetachedCriteria.forClass(Source.class).setProjection(Projections.rowCount()).add(Restrictions.idEq(request.id().getId())); – user590444 Apr 27 '12 at 10:41
In SQL. http://stackoverflow.com/questions/1676551/best-way-to-test-if-a-row-exists-in-a-mysql-table – James P. Aug 12 '13 at 15:49

The fastest way to check if some records in a database table using hibernate

1 Answers1