how to add @ to postgres hibernate dialect?

hibernate postgresql full-text-search hql

you can find it in this link, that link will guide you to :

recognize that SQLFunctions have to return a value and when used inHQL must be in an expression form (e.g., fts(body, 'dog') = true --fts(body, 'dog') won't work in HQL)
create a Hibernate SQLFunction for PG FTS; and
remember that the expression "to_tsvector(body) @@ to_tsquery('dog')"evaluates to a boolean

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