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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>3.2. Views</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><link rel="prev" href="tutorial-advanced-intro.html" title="3.1. Introduction" /><link rel="next" href="tutorial-fk.html" title="3.3. Foreign Keys" /></head><body id="docContent" class="container-fluid col-10"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">3.2. Views</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="tutorial-advanced-intro.html" title="3.1. Introduction">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="tutorial-advanced.html" title="Chapter 3. Advanced Features">Up</a></td><th width="60%" align="center">Chapter 3. Advanced Features</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 16.3 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="tutorial-fk.html" title="3.3. Foreign Keys">Next</a></td></tr></table><hr /></div><div class="sect1" id="TUTORIAL-VIEWS"><div class="titlepage"><div><div><h2 class="title" style="clear: both">3.2. Views <a href="#TUTORIAL-VIEWS" class="id_link">#</a></h2></div></div></div><a id="id-1.4.5.3.2" class="indexterm"></a><p>
Refer back to the queries in <a class="xref" href="tutorial-join.html" title="2.6. Joins Between Tables">Section 2.6</a>.
Suppose the combined listing of weather records and city location
is of particular interest to your application, but you do not want
to type the query each time you need it. You can create a
<em class="firstterm">view</em> over the query, which gives a name to
the query that you can refer to like an ordinary table:
</p><pre class="programlisting">
CREATE VIEW myview AS
SELECT name, temp_lo, temp_hi, prcp, date, location
FROM weather, cities
WHERE city = name;
SELECT * FROM myview;
</pre><p>
</p><p>
Making liberal use of views is a key aspect of good SQL database
design. Views allow you to encapsulate the details of the
structure of your tables, which might change as your application
evolves, behind consistent interfaces.
</p><p>
Views can be used in almost any place a real table can be used.
Building views upon other views is not uncommon.
</p></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="tutorial-advanced-intro.html" title="3.1. Introduction">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="tutorial-advanced.html" title="Chapter 3. Advanced Features">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="tutorial-fk.html" title="3.3. Foreign Keys">Next</a></td></tr><tr><td width="40%" align="left" valign="top">3.1. Introduction </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 16.3 Documentation">Home</a></td><td width="40%" align="right" valign="top"> 3.3. Foreign Keys</td></tr></table></div></body></html>
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