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37      <p>
38                   To modify a stored entity object, retrieve it, update
39                   it, then put it back to the entity store:
40           </p>
41      <pre class="programlisting">
42SimpleEntityClass sec = sda.pIdx.get("keyone");
43sec.setsKey("skeyoneupdated");
44sda.pIdx.put(sec);
45</pre>
46      <p>
47                Note that because we updated a field on the object that is
48                a secondary key, this object will now be accessible by the
49                secondary key of <tt class="literal">skeyoneupdated</tt> instead
50                of the previous value, which was <tt class="literal">skeyone</tt>
51        </p>
52      <p>
53                Be aware that if you modify the object's primary key, the behavior is
54                somewhat different. In this case, you cause a new instance
55                of the object to be created in the store, instead of
56                replacing an existing instance:
57        </p>
58      <pre class="programlisting">// Results in two objects in the store.  One with a
59// primary index of "keyfive" and the other with primary index of 
60//'keyfivenew'.
61SimpleEntityClass sec = sda.pIdx.get("keyfive");
62sec.setpKey("keyfivenew");
63sda.pIdx.put(sec); </pre>
64      <p>
65                Finally, if you are iterating over a collection of objects
66                using an <tt class="classname">EntityCursor</tt>, you can
67                update each object in turn using
68                <tt class="methodname">EntityCursor.update()</tt>. Note,
69                however, that you must be iterating using a
70                <tt class="classname">PrimaryIndex</tt>; this operation is not
71                allowed if you are using a
72                <tt class="classname">SecondaryIndex</tt>.
73        </p>
74      <p>
75                For example, the following iterates over every
76                <tt class="classname">SimpleEntityClass</tt> object in the entity
77                store, and it changes them all so that they have a
78                secondary index of <tt class="literal">updatedskey</tt>:
79        </p>
80      <pre class="programlisting">EntityCursor&lt;SimpleEntityClass&gt; sec_pcursor = sda.pIdx.entities();
81for (SimpleEntityClass sec : sec_pcursor) {
82    sec.setsKey("updatedskey");
83    sec_pcursor.update(item);
84}
85sec_pcursor.close(); </pre>
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