shell% cat concrete.sql 
 select city, date from weather where temp_lo < 20;
 shell% sql_test concrete.sql 
 shell% cat testexec.out # see results of prepare, execute on this
##</code><code>##

 shell% cat abstract.sql
 select city, date from weather where temp_lo < ?;
 shell% sql_test abstract.sql 55 # send in placeholder value
 shell% cat testexec.out # to see results... looks good
##</code><code>##

 shell% sql_register abstract.sql basic_weather
 [hi_and_low] inserted as 
 [select city from weather where temp_lo > ? and temp_hi > ? LIMIT 10]
##</code><code>##

 ... then in a Perl program (e.g. test.pl in this distribution)
 my $dbh = SQL::Catalog->db_handle; # optional - get the handle as you please
 my $sql = SQL::Catalog->lookup('hi_and_low');
 my $sth = $dbh->prepare($sql);
 $sth->execute(55);
##</code><code>##

 my $rows = $sth->rows;

##</code><code>##

 [city_date_via_temp_hi] saved as
 [select city, date from weather where temp_hi > ?] 
##</code><code>##

 my $dbh = SQL::Catalog->db_handle;
 my $SQL = SQL::Catalog->lookup('city_date_via_temp_hi') or die 'not found';
 my $sth = $dbh->prepare($SQL, $cgi->param('degrees'));
  .... etc
##</code><code>##

 CREATE TABLE sql_catalog (
	query varchar(65535) , # the actual query
	tables varchar(255) ,  # tables used
	columns varchar(255) , # fields selected
	cmd varchar(40) ,      # SELECT, INSERT, UPDATE, etc
	phold int4   # number of bind_values
 );

##</code><code>##

 mydb=# select label,cmd,columns,tables,phold from sql_catalog;
      label     |  cmd   | columns                          | tables  | phold 
 ---------------+--------+---------------------------------------------------
 weather_hi    | SELECT | weather.city,weather.date        | weather |     1
 hi_and_low    | SELECT | weather.city                     | weather |     2