NAME
    Oracle::Trigger - Perl class for creating Oracle triggers

SYNOPSIS
      use Oracle::Trigger;

      my %cfg = ('conn_string'=>'usr/pwd@db', 'table_name'=>'my_ora_tab');
      my $ot = Oracle::Trigger->new;
      # or combine the two together
      my $ot = Oracle::Trigger->new(%cfg);
      my $sql= $ot->prepare(%cfg); 
      $ot->execute();    # actually create the audit table and trigger

DESCRIPTION
    This class contains methods to create audit tables and triggers for
    Oracle tables.

  new (conn_string=>'usr/pwd@db',table_name=>'my_table')

    Input variables:

      $cs  - Oracle connection string in usr/pwd@db
      $tn  - Oracle table name without schema

    Variables used or routines called:

      None

    How to use:

       my $obj = new Oracle::Trigger;      # or
       my $obj = Oracle::Trigger->new;     # or
       my $cs  = 'usr/pwd@db';
       my $tn  = 'my_table'; 
       my $obj = Oracle::Trigger->new(cs=>$cs,tn=>$tn); # or
       my $obj = Oracle::Trigger->new('cs',$cs, 'tn',$tn); 

    Return: new empty or initialized Oracle::Trigger object.

    This method constructs a Perl object and capture any parameters if
    specified. It creates and defaults the following variables:

      $self->{conn_string} = "";       # or $self->{cs}
      $self->{table_name}  = "";       # or $self->{tn}  

METHODS
    The following are the common methods, routines, and functions defined in
    this classes.

  Exported Tag: All

    The *:all* tag includes all the methods or sub-rountines defined in this
    class.

      use Oracle::Trigger qw(:all);

    It includes the following sub-routines: =head3 prepare($cs, $tn, $tp)

    Input variables:

      $cs  - Oracle connection string in usr/pwd@db
      $tn  - Oracle table name without schema
      $tp  - trigger type
             DATA - trigger to audit a table. This is the default.

    Variables used or routines called:

      Debug::EchoMessage
        echoMSG - display message
      {cs} - connection string
      {tn} - table name 
      {drop_audit}   - whether to drop audit table if it exists
      {audit_table}  - audit table name, default to aud${$tn}
      {trigger_name} - trigger name, default to trg${$tn}

    How to use:

      my $ar = $self->prepare('usr/pwd@db','my_tab');

    Return: $hr - a hash array ref containing the following keys:

      dbh         - the database handler
      sql_audit   - SQL statement for creating the audit table
      sql_trigger - SQL statement for creating the trigger

    This method performs the following tasks:

      1) create a database handler
      2) check the existance of the table 
      3) generate script for creating audit table
      4) generate script for creating trigger

    And it sets the following internal variable as well:

      {dbh} - database handler
      {sql_audit} - sql statements to create audit table
      {sql_trigger} - sql statement to create trigger

   execute($typ)

    Input variables:

      $typ - action type:
             TRIGGER - create trigger only 
             AUDIT   - create audit table only
             default - null and will create both

    Variables used or routines called:

      {dbh} - database handler
      {sql_audit} - sql statements to create audit table
      {sql_trigger} - sql statement to create trigger

    How to use:

      my $status = $self->execute();
      $self->execute();

    Return: 0|1: 0 - OK; 1 - failed

    This method submits the sql statement to Oracle server to create audit
    table or trigger or both. The default is to create both. If the audit
    table exists, it will skip creating the audit table. You either need to
    manually drop the table or set {drop_audit} to '1' before you run
    prepare().

HISTORY
    * Version 0.1
        This version is to test the procedures and create DATA trigger.

        04/22/2005 (htu) - finished creating DATA trigger rountines.

    * Version 0.2
        04/29/2005 (htu) - modified some descriptions and moved the common
        routines to Oracle::DML::Common.

SEE ALSO (some of docs that I check often)
        Data::Describe, Oracle::Loader, CGI::Getopt, File::Xcopy,
        perltoot(1), perlobj(1), perlbot(1), perlsub(1), perldata(1),
        perlsub(1), perlmod(1), perlmodlib(1), perlref(1), perlreftut(1).

AUTHOR
        Copyright (c) 2005 Hanming Tu. All rights reserved.

        This package is free software and is provided "as is" without
        express or implied warranty. It may be used, redistributed and/or
        modified under the terms of the Perl Artistic License (see
        http://www.perl.com/perl/misc/Artistic.html)