10.5. Using EL in EJB-QL/HQL

Seam proxies the EntityManager or Session object whenever you use a Seam-managed persistence context or inject a container-managed persistence context with @PersistenceContext. This lets you safely and efficiently use EL expressions in your query strings. For example, this:

User user = em.createQuery("from User where username=#{user.username}")
                          .getSingleResult();

User user = em.createQuery("from User where username=#{user.username}")
                          .getSingleResult();

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is equivalent to:

User user = em.createQuery("from User where username=:username")
                          .setParameter("username", user.getUsername()) 
                          .getSingleResult();

User user = em.createQuery("from User where username=:username")
                          .setParameter("username", user.getUsername()) 
                          .getSingleResult();

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Warning

Do not use the format below, because it is vulnerable to SQL injection attacks, as well as being inefficient.

User user = em.createQuery("from User where username=" + user.getUsername()).getSingleResult(); //BAD!

User user = em.createQuery("from User where username=" + user.getUsername()).getSingleResult(); //BAD!

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10.5. Using EL in EJB-QL/HQL

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