Update/correct inheritance examples.

This commit is contained in:
Tom Lane 2002-04-13 17:17:29 +00:00
parent 6f2c0d47f8
commit 291c875f23

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@ -1,5 +1,5 @@
<!-- <!--
$Header: /cvsroot/pgsql/doc/src/sgml/Attic/inherit.sgml,v 1.18 2002/01/07 02:29:12 petere Exp $ $Header: /cvsroot/pgsql/doc/src/sgml/Attic/inherit.sgml,v 1.19 2002/04/13 17:17:29 tgl Exp $
--> -->
<chapter id="inherit"> <chapter id="inherit">
@ -56,35 +56,28 @@ SELECT name, altitude
which returns: which returns:
<programlisting> <programlisting>
+----------+----------+ name | altitude
|name | altitude | -----------+----------
+----------+----------+ Las Vegas | 2174
|Las Vegas | 2174 | Mariposa | 1953
+----------+----------+ Madison | 845
|Mariposa | 1953 |
+----------+----------+
|Madison | 845 |
+----------+----------+
</programlisting> </programlisting>
</para> </para>
<para> <para>
On the other hand, the following query finds On the other hand, the following query finds
all the cities that are not state capitals and all the cities that are not state capitals and
are situated at an altitude of 500ft or higher: are situated at an altitude over 500ft:
<programlisting> <programlisting>
SELECT name, altitude SELECT name, altitude
FROM ONLY cities FROM ONLY cities
WHERE altitude &gt; 500; WHERE altitude &gt; 500;
+----------+----------+ name | altitude
|name | altitude | -----------+----------
+----------+----------+ Las Vegas | 2174
|Las Vegas | 2174 | Mariposa | 1953
+----------+----------+
|Mariposa | 1953 |
+----------+----------+
</programlisting> </programlisting>
</para> </para>
@ -112,18 +105,16 @@ SELECT name, altitude
which returns: which returns:
<programlisting> <programlisting>
+---------+----------+----------+ tableoid | name | altitude
|tableoid |name | altitude | ----------+-----------+----------
+---------+----------+----------+ 139793 | Las Vegas | 2174
|37292 |Las Vegas | 2174 | 139793 | Mariposa | 1953
+---------+----------+----------+ 139798 | Madison | 845
|37280 |Mariposa | 1953 |
+---------+----------+----------+
|37280 |Madison | 845 |
+---------+----------+----------+
</programlisting> </programlisting>
If you do a join with pg_class you can see the actual table name: (If you try to reproduce this example, you will probably get different
numeric OIDs.) By doing a join with pg_class you can see the actual table
names:
<programlisting> <programlisting>
SELECT p.relname, c.name, c.altitude SELECT p.relname, c.name, c.altitude
@ -134,15 +125,11 @@ SELECT name, altitude
which returns: which returns:
<programlisting> <programlisting>
+---------+----------+----------+ relname | name | altitude
|relname |name | altitude | ----------+-----------+----------
+---------+----------+----------+ cities | Las Vegas | 2174
|capitals |Las Vegas | 2174 | cities | Mariposa | 1953
+---------+----------+----------+ capitals | Madison | 845
|cities |Mariposa | 1953 |
+---------+----------+----------+
|cities |Madison | 845 |
+---------+----------+----------+
</programlisting> </programlisting>
</para> </para>