diff options
Diffstat (limited to 'doc/src/sgml/inherit.sgml')
| -rw-r--r-- | doc/src/sgml/inherit.sgml | 42 |
1 files changed, 18 insertions, 24 deletions
diff --git a/doc/src/sgml/inherit.sgml b/doc/src/sgml/inherit.sgml index 0593da09155..0a49df2c510 100644 --- a/doc/src/sgml/inherit.sgml +++ b/doc/src/sgml/inherit.sgml @@ -6,7 +6,7 @@ state capitals which are also cities. Naturally, the capitals class should inherit from cities. - <programlisting> +<programlisting> CREATE TABLE cities ( name text, population float, @@ -16,7 +16,7 @@ CREATE TABLE cities ( CREATE TABLE capitals ( state char(2) ) INHERITS (cities); - </programlisting> +</programlisting> In this case, an instance of capitals <firstterm>inherits</firstterm> all attributes (name, population, and altitude) from its @@ -40,19 +40,17 @@ CREATE TABLE capitals ( For example, the following query finds all the cities that are situated at an attitude of 500ft or higher: - <programlisting> +<programlisting> SELECT name, altitude FROM cities WHERE altitude > 500; -+----------+----------+ -|name | altitude | -+----------+----------+ -|Las Vegas | 2174 | -+----------+----------+ -|Mariposa | 1953 | -+----------+----------+ - </programlisting> + name | altitude +-----------+---------- + Las Vegas | 2174 + Mariposa | 1953 +(2 rows) +</programlisting> </para> <para> @@ -60,25 +58,21 @@ SELECT name, altitude including state capitals, that are located at an altitude over 500ft, the query is: - <programlisting> +<programlisting> SELECT c.name, c.altitude FROM cities* c WHERE c.altitude > 500; - </programlisting> +</programlisting> which returns: - <programlisting> -+----------+----------+ -|name | altitude | -+----------+----------+ -|Las Vegas | 2174 | -+----------+----------+ -|Mariposa | 1953 | -+----------+----------+ -|Madison | 845 | -+----------+----------+ - </programlisting> +<programlisting> + name | altitude +-----------+---------- + Las Vegas | 2174 + Mariposa | 1953 + Madison | 845 +</programlisting> Here the <quote>*</quote> after cities indicates that the query should be run over cities and all classes below cities in the |