Spring Hibernate and PostgresSQL Full Text Search - spring

Question

How to implement FTS with Hibernate, Spring and PostgresSQL. Can I put some paramters in Hibernate #Formula annotation so I could put score as extra select paramter:
select *,
ts_rank_cd(to_tsvector(title || ' ' || code || ' ' || line1 || ' ' || postal || ' ' || city),
to_tsquery('LA | Los Anageles')) AS score
from customer
where score > 0
order by score desc;
and how to do it with Spirng Specifications, now I have:
if (!StringUtils.isEmpty(search)) {
spec = Objects.requireNonNull(spec).and((root, query, cb) -> cb.or(
cb.like(cb.lower(root.get(Customer_.title)), "%" + search.toLowerCase() + "%"),
cb.like(cb.lower(root.get(Customer_.code)), "%" + search.toLowerCase() + "%"),
cb.like(cb.lower(root.get(Customer_.address).get(Address_.line1)), search.toLowerCase() + "%"),
cb.like(cb.lower(root.get(Customer_.address).get(Address_.postal)), search.toLowerCase() + "%"),
cb.like(cb.lower(root.get(Customer_.address).get(Address_.city)), search.toLowerCase() + "%")
));
}
could I used at least cb.function withoud sorting by score?

Answer 1

You will have to implement a custom SQLFunction and register that under a name in Hibernate. You can then use the function by that name through cb.function.
Alternatively you should also be able to use the following:
cb.function("ts_rank_cd", String.class,
cb.function("to_tsvector", String.class,
cb.concat(...),
cb.function("to_tsquery", String.class, cb.literal("LA | Los Anageles"))
)
).as(Double.class);
This should result in SQL similar to this:
cast(ts_rank_cd(to_tsvector(title || ' ' || code || ' ' || line1 || ' ' || postal || ' ' || city), to_tsquery('LA | Los Anageles')) as double precision)