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      <p class="MsoNormal">Ναι μπορεί να χρησιμοποιηθεί το <span
          style="mso-ansi-language:EN-US" lang="EN-US">aggregation</span>
        όπως αναφέρεται στο βιβλίο
        και στις διαφάνειες. Ως ορολογία είχα τον όρο <span
          style="mso-ansi-language:EN-US" lang="EN-US">aggregation</span>.</p>
      <br>
      On 5/11/2016 9:42 μμ, Παναγιώτης Καραμπάσης wrote:<br>
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    <blockquote
cite="mid:CAFWR4pkGYSsdpZDdbqkS6+bbFBtNzksYpD4KcYm2nQfRkT5k0w@mail.gmail.com"
      type="cite">
      <div dir="ltr">
        <div>Καλησπέρα,<br>
        </div>
        <div><br>
          Θα ήθελα να παραπέμψω στην ενότητα 7.8.5 Aggregation του
          βιβλίου του μαθήματος Database System Concepts, Silberschatz,
          Korth, Sudershan, 6th Edition.<br>
          <br>
        </div>
        <div><i>Aggregation is an abstraction through which
            relationships are treated as higher-level entities. [...]
            Such an entity set is treated in the same manner as any
            other entity set.</i><br>
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        <div><br>
          Είναι κάτι που χρησιμοποίησα στο μοντέλο μου, ελπίζω να μην
          απαγορευτεί για κάποιο λόγο.<br>
          <br>
        </div>
        Ευχαριστώ.<br>
      </div>
      <br>
      <div class="gmail_quote">
        <div dir="ltr">Στις Σάβ, 5 Νοε 2016 στις 9:27 μ.μ., ο/η Theodora
          Galani &lt;<a moz-do-not-send="true"
            href="mailto:theodora@dblab.ece.ntua.gr">theodora@dblab.ece.ntua.gr</a>&gt;
          έγραψε:<br>
        </div>
        <blockquote class="gmail_quote" style="margin:0 0 0
          .8ex;border-left:1px #ccc solid;padding-left:1ex">
          <div bgcolor="#FFFFFF" text="#000000" class="gmail_msg">
            <div class="m_3988535163947673014moz-cite-prefix gmail_msg">Ένα
              σύνολο συσχετίσεων συνδέει δύο (ή περισσότερα) σύνολα
              οντοτήτων.<br class="gmail_msg">
              Δεν μπορεί ένα σύνολο συσχετίσεων να συνδέει άλλα σύνολα
              συσχετίσεων μεταξύ τους.<br class="gmail_msg">
              <br class="gmail_msg">
              On 5/11/2016 8:15 μμ, John Sig wrote:<br class="gmail_msg">
            </div>
            <blockquote type="cite" class="gmail_msg">
              <div
style="color:#000;background-color:#fff;font-family:HelveticaNeue,Helvetica
                Neue,Helvetica,Arial,Lucida
                Grande,sans-serif;font-size:16px" class="gmail_msg">
                <div
                  id="m_3988535163947673014yui_3_16_0_ym19_1_1478368337718_29673"
                  class="gmail_msg">Καλησπέρα,<br class="gmail_msg">
                </div>
                <div class="m_3988535163947673014qtdSeparateBR
                  gmail_msg"><br class="gmail_msg">
                  <br class="gmail_msg">
                </div>
                <div class="m_3988535163947673014yahoo_quoted gmail_msg"
id="m_3988535163947673014yui_3_16_0_ym19_1_1478368337718_29692"
                  style="display:block">
                  <div style="font-family:HelveticaNeue,Helvetica
                    Neue,Helvetica,Arial,Lucida
                    Grande,sans-serif;font-size:16px"
                    id="m_3988535163947673014yui_3_16_0_ym19_1_1478368337718_29691"
                    class="gmail_msg">
                    <div style="font-family:HelveticaNeue,Helvetica
                      Neue,Helvetica,Arial,Lucida
                      Grande,sans-serif;font-size:16px"
                      id="m_3988535163947673014yui_3_16_0_ym19_1_1478368337718_29690"
                      class="gmail_msg">
                      <div class="m_3988535163947673014y_msg_container
                        gmail_msg"
                        id="m_3988535163947673014yui_3_16_0_ym19_1_1478368337718_29718">
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                          class="gmail_msg">
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                            class="m_3988535163947673014yiv3028243825yqt0971225874
                            gmail_msg"
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                            <div
                              id="m_3988535163947673014yui_3_16_0_ym19_1_1478368337718_29717"
                              class="gmail_msg">
                              <div
style="color:#000;background-color:#fff;font-family:HelveticaNeue,Helvetica
                                Neue,Helvetica,Arial,Lucida
                                Grande,sans-serif;font-size:16px"
                                id="m_3988535163947673014yui_3_16_0_ym19_1_1478368337718_29716"
                                class="gmail_msg">
                                <div
                                  class="m_3988535163947673014yiv3028243825qtdSeparateBR
                                  gmail_msg"
                                  id="m_3988535163947673014yui_3_16_0_ym19_1_1478368337718_29715"><br
                                    class="gmail_msg" clear="none">
                                  <br class="gmail_msg" clear="none">
                                </div>
                                <div
                                  class="m_3988535163947673014yiv3028243825yahoo_quoted
                                  gmail_msg"
id="m_3988535163947673014yiv3028243825yui_3_16_0_ym19_1_1478368337718_16477"
                                  style="display:block">
                                  <div
id="m_3988535163947673014yiv3028243825yui_3_16_0_ym19_1_1478368337718_16476"
style="font-family:HelveticaNeue,Helvetica Neue,Helvetica,Arial,Lucida
                                    Grande,sans-serif;font-size:16px"
                                    class="gmail_msg">
                                    <div
id="m_3988535163947673014yiv3028243825yui_3_16_0_ym19_1_1478368337718_16475"
style="font-family:HelveticaNeue,Helvetica Neue,Helvetica,Arial,Lucida
                                      Grande,sans-serif;font-size:16px"
                                      class="gmail_msg">
                                      <div
                                        class="m_3988535163947673014yiv3028243825y_msg_container
                                        gmail_msg"
id="m_3988535163947673014yiv3028243825yui_3_16_0_ym19_1_1478368337718_16480">
                                        <div
                                          id="m_3988535163947673014yiv3028243825"
                                          class="gmail_msg">
                                          <div
id="m_3988535163947673014yiv3028243825yui_3_16_0_ym19_1_1478368337718_16479"
                                            class="gmail_msg">
                                            <div
id="m_3988535163947673014yiv3028243825yui_3_16_0_ym19_1_1478368337718_16478"
style="color:#000;background-color:#fff;font-family:HelveticaNeue,Helvetica
Neue,Helvetica,Arial,Lucida Grande,sans-serif;font-size:16px"
                                              class="gmail_msg">
                                              <div dir="ltr"
id="m_3988535163947673014yiv3028243825yui_3_16_0_ym19_1_1478368337718_2420"
                                                class="gmail_msg">είναι
                                                δυνατόν στο μοντέλο ER
                                                να έχουμε συσχέτιση
                                                συσχετίσεων,</div>
                                              <div dir="ltr"
id="m_3988535163947673014yiv3028243825yui_3_16_0_ym19_1_1478368337718_2420"
                                                class="gmail_msg">δηλαδή
                                                μία οντότητα να συνδέει
                                                μία συσχέτιση με μία
                                                άλλη συσχέτιση;</div>
                                              <div dir="ltr"
id="m_3988535163947673014yiv3028243825yui_3_16_0_ym19_1_1478368337718_2420"
                                                class="gmail_msg"><br
                                                  class="gmail_msg"
                                                  clear="none">
                                              </div>
                                              <div dir="ltr"
id="m_3988535163947673014yiv3028243825yui_3_16_0_ym19_1_1478368337718_2420"
                                                class="gmail_msg">Ευχαριστώ.</div>
                                            </div>
                                          </div>
                                        </div>
                                        <br class="gmail_msg"
                                          clear="none">
                                        <br class="gmail_msg"
                                          clear="none">
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                        </div>
                        <br class="gmail_msg">
                        <br class="gmail_msg">
                      </div>
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              </div>
              <br class="gmail_msg">
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                gmail_msg"></fieldset>
              <br class="gmail_msg">
              <pre class="gmail_msg">_______________________________________________
Db mailing list
<a moz-do-not-send="true" class="m_3988535163947673014moz-txt-link-abbreviated gmail_msg" href="mailto:Db@lists.cslab.ece.ntua.gr" target="_blank">Db@lists.cslab.ece.ntua.gr</a>
<a moz-do-not-send="true" class="m_3988535163947673014moz-txt-link-freetext gmail_msg" href="http://lists.cslab.ece.ntua.gr/mailman/listinfo/db" target="_blank">http://lists.cslab.ece.ntua.gr/mailman/listinfo/db</a>
</pre>
            </blockquote>
            <p class="gmail_msg"><br class="gmail_msg">
            </p>
          </div>
          _______________________________________________<br
            class="gmail_msg">
          Db mailing list<br class="gmail_msg">
          <a moz-do-not-send="true"
            href="mailto:Db@lists.cslab.ece.ntua.gr" class="gmail_msg"
            target="_blank">Db@lists.cslab.ece.ntua.gr</a><br
            class="gmail_msg">
          <a moz-do-not-send="true"
            href="http://lists.cslab.ece.ntua.gr/mailman/listinfo/db"
            rel="noreferrer" class="gmail_msg" target="_blank">http://lists.cslab.ece.ntua.gr/mailman/listinfo/db</a><br
            class="gmail_msg">
        </blockquote>
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    </blockquote>
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