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javasqljpaeclipselink

How do I find a value in a column that just have unique values with EclipseLink?

You have the EntityManager.find(Class entityClass, Object primaryKey) method to find a specific row with a primary key.

But how do I find a value in a column that just have unique values and is not a primary key?

Solution

  • For example, like this:

    List<T> results = em.createQuery("SELECT t FROM TABLE t", T.class)
                        .getResultList();

    With parameters:

    List<T> results = em.createQuery("SELECT t FROM TABLE t where t.value = :value1")
                        .setParameter("value1", "some value").getResultList();

    For single result replace getResultList() with getSingleResult():

    T entity = em.createQuery("SELECT t FROM TABLE t where t.uniqueKey = :value1")
                 .setParameter("value1", "KEY1").getSingleResult();

    One other way is to use Criteria API.