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copied!<p>Do you mean a HQL query? Well, a typical query on your <code>Leavetable</code> entity would looks like this:</p> <pre><code>Query q = session.createQuery("from Leavetable t where t.someField = :value"); q.setParameter("value", foo); List<Leavetable> results = q.list(); </code></pre> <hr> <p>However, if you just want to retrieve an entity by identifier, see <a href="http://docs.jboss.org/hibernate/stable/core/api/org/hibernate/Session.html#load(java.lang.Class,%20java.io.Serializable)" rel="nofollow noreferrer"><code>Session#load()</code></a> or <a href="http://docs.jboss.org/hibernate/stable/core/api/org/hibernate/Session.html#get%28java.lang.Class,%20java.io.Serializable%29" rel="nofollow noreferrer"><code>Session#get()</code></a>. I don't want to make things too much confusing but while both methods are similar, there is an important difference between both of them. Quoting the <a href="https://forum.hibernate.org/viewtopic.php?p=2387456" rel="nofollow noreferrer">Hibernate Forums</a>:</p> <blockquote> <h3>Retrieving objects by identifier</h3> <p>The following Hibernate code snippet retrieves a User object from the database:</p> <pre><code>User user = (User) session.get(User.class, userID); </code></pre> <p>The <code>get()</code> method is special because the identifier uniquely identifies a single instance of a class. Hence it’s common for applications to use the identifier as a convenient handle to a persistent object. Retrieval by identifier can use the cache when retrieving an object, avoiding a database hit if the object is already cached. Hibernate also provides a <code>load()</code> method:</p> <pre><code>User user = (User) session.load(User.class, userID); </code></pre> <p>The load() method is older; get() was added to Hibernate’s API due to user request. The difference is trivial:</p> <p>If <code>load()</code> can’t find the object in the cache or database, an exception is thrown. The load() method never returns null. The <code>get()</code> method returns <code>null</code> if the object can’t be found.</p> <p>The <code>load()</code> method may return a proxy instead of a real persistent instance. A proxy is a placeholder that triggers the loading of the real object when it’s accessed for the first time; we discuss proxies later in this section. On the other hand, <code>get()</code> never returns a proxy.</p> <p><strong>Choosing between <code>get()</code> and <code>load()</code> is easy:</strong> If you’re certain the persistent object exists, and nonexistence would be considered exceptional, <code>load()</code> is a good option. If you aren’t certain there is a persistent instance with the given identifier, use <code>get()</code> and test the return value to see if it’s null. Using <code>load()</code> has a further implication: The application may retrieve a valid reference (a proxy) to a persistent instance without hitting the database to retrieve its persistent state. So <code>load()</code> might not throw an exception when it doesn’t find the persistent object in the cache or database; the exception would be thrown later, when the proxy is accessed.</p> <p>Of course, retrieving an object by identifier isn’t as flexible as using arbitrary queries.</p> </blockquote> <p>See also the Hibernate Documentation (links below).</p> <h3>Reference</h3> <ul> <li>Hibernate Core Reference Guide <ul> <li><a href="http://docs.jboss.org/hibernate/core/3.5/reference/en/html/objectstate.html#objectstate-loading" rel="nofollow noreferrer">10.3. Loading an object</a></li> <li><a href="http://docs.jboss.org/hibernate/core/3.3/reference/en/html/queryhql.html" rel="nofollow noreferrer">Chapter 14. HQL: The Hibernate Query Language</a> </li> </ul></li> </ul>

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