Case-insensitive search using Hibernate

Question

For the simple case you describe, look at Restrictions.ilike(), which does a case-insensitive search.

Criteria crit = session.createCriteria(Person.class);
crit.add(Restrictions.ilike('town', '%fran%');
List results = crit.list();

Criteria crit = session.createCriteria(Person.class);
crit.add(Restrictions.ilike('town', 'fran', MatchMode.ANYWHERE);
List results = crit.list();

If you use Spring's HibernateTemplate to interact with Hibernate, here is how you would do a case insensitive search on a user's email address:

getHibernateTemplate().find("from User where upper(email)=?", emailAddr.toUpperCase());

You also do not have to put in the '%' wildcards. You can pass MatchMode (docs for previous releases here) in to tell the search how to behave. START, ANYWHERE, EXACT, and END matches are the options.

The usual approach to ignoring case is to convert both the database values and the input value to upper or lower case - the resultant sql would have something like

select f.name from f where TO_UPPER(f.name) like '%FRAN%'

In hibernate criteria restrictions.like(...).ignoreCase()

I'm more familiar with Nhibernate so the syntax might not be 100% accurate

for some more info see pro hibernate 3 extract and hibernate docs 15.2. Narrowing the result set

This can also be done using the criterion Example, in the org.hibernate.criterion package.

public List findLike(Object entity, MatchMode matchMode) {
    Example example = Example.create(entity);
    example.enableLike(matchMode);
    example.ignoreCase();
    return getSession().createCriteria(entity.getClass()).add(
            example).list();
}

Just another way that I find useful to accomplish the above.