Object Query Language

<h2 id="general-rules">General rules</h2>
<p>The following rules apply to OQL statements:
</p>
<ul><li>All complete statements must be terminated by a semi-colon.</li>
<li>A list of entries in OQL is usually separated by commas but not terminated by a comma(,).</li>
<li>Strings of text are enclosed by matching quotation marks.</li></ul>
<h2 id="examples">Examples</h2>
<h3>Simple query</h3>
<p>The following example illustrates how one might retrieve the <a href="/facts/CPU/Jxp1bqMV">CPU</a>-speed of all PCs with more than 64MB of <a href="/facts/Random-access_memory/DuD4bxh6">RAM</a> from a fictional <a href="/facts/Personal_computer/koaYfNce">PC</a> database:
</p>
SELECT pc.cpuspeed
FROM PCs pc
WHERE pc.ram > 64;

<h3>Query with grouping and aggregation</h3>
<p>The following example illustrates how one might retrieve the average amount of <a href="/facts/Random-access_memory/DuD4bxh6">RAM</a> on a <a href="/facts/Personal_computer/koaYfNce">PC</a>, grouped by manufacturer:
</p>
SELECT manufacturer, AVG(SELECT part.pc.ram FROM partition part)
FROM PCs pc
GROUP BY manufacturer: pc.manufacturer;

<p>Note the use of the keyword partition, as opposed to aggregation in traditional SQL.
</p>

<ul><li>Dietrich, Suzanne; Urban, Susan (31 May 2022). <a href="https://books.google.com/books?id=JYdyEAAAQBAJ&dq=%22Object+Query+Language%22+-wikipedia&pg=PA31">"2.4 The ODMG Query Language"</a>. <i>Fundamentals of Object Databases</i>. <a href="/facts/Springer_Nature/TpTgApAh">Springer Nature</a>. pp. 31–52. <a href="/facts/ISBN_(identifier)/15AdSPa9">ISBN</a> 978-3-031-01844-2.</li></ul>
<ul><li>Cattell, Roderic Geoffrey Galton; Barry, Douglas K.; Berler, Mark (2000). "Object Query Language". <a href="https://books.google.com/books?id=2-FF-aQ_twQC"><i>The Object Data Standard: ODMG 3.0</i></a>. <a href="/facts/Morgan_Kaufmann/HfefrWju">Morgan Kaufmann</a>. pp. 89–152. <a href="/facts/ISBN_(identifier)/15AdSPa9">ISBN</a> 978-1-55860-647-0. Retrieved 31 March 2025.</ref></li></ul>

<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/Object_Data_Management_Group/3DGvyppC">Object Data Management Group</a> (ODMG)</li>
<li>Object Definition Language</li></ul>
<h2 id="references">References</h2>

Object Query Language open-in-new

Object Query Language