MAN page from Old RedHat 7.X perl-SQL-Schema-0.31-8.i386.rpm

SQL::Schema::Table::Column

Section: User Contributed Perl Documentation (3)
Updated: perl v5.6.0
Index

NAME

SQL::Schema::Table::Column - A column of a database table

SYNOPSIS

  my $column = SQL::Schema::Table::Column->new(%attr);

  my $sql = $column->column_definition;  print $sql;

  print "$column";

DESCRIPTION

`SQL::Schema::Table::Column' is a class for objects representing a databasetable's column. The methods of an instanciated object do allow to access theinformation within a database's data dictionary and to represent them as SQLcreate statements and the like using the proper SQL dialect.

Constructors

  $column = SQL::Schema::Table::Column->new(%attr);

The new method instanciates a column object. The object isan in memory representation of a (possible) database table's column.The attributes are given as key value pairs by the hash `%attr'.Possible keys are:

  key              required?   value description

  column_name      yes         The name of the table's column.

  data_type        yes         number  data_length      no          number  data_precision   no          number  data_scale       no          number  nullable         no          either `Y' o `N'; default: `Y'  data_default     no          a character string approbriate as                               expression after the `default' keyword                               (might include quotes)

These keys and their possible values correspond exactly to thedata dictionary view `all_tab_columns' and are described withinOracle's Server Reference.

  $column = SQL::Schema::Table::Column->select($dbh,$table_name,$column_name);

The select method fetches the attributes required by newfrom the database and returns the column object. (It calls newinternally.)

If the column could not be found within the database, the method returns undef.

The method's arguments are as follows:

`$dbh': A database handle as defined by DBI(3).
`$table_name': The name of the table without preceeding schema name.
`$column_name': The name of the column.

Methods

The following attribute methods do return the current valueof the attributes (as handed over to the new method):

  $column_name = $column->name;  $data_type = $column->data_type;  $data_length = $column->data_length;  $data_precision = $column->data_precision;  $data_scale = $column->data_scale;  $nullable = $column->nullable;  $data_default = $column->data_default;

There does exist a speciallity for the `data_default' method:If the attribute `data_default' the method `data_default'returns the content of the attribute with eleminated trailing new line.

The return value of nullable is either `Y' or `N'.This is somewhat uncomfortable for perl programmers.You might want to use the following method instead:

  $nullable = $sequence->nullable_bool;

It does return `1' resp. `0' where its correspondingattribute method returns `Y' resp. `N'.

  $sql = $column->column_definition;  $sql = "$column";

Returns a string containing the column definition which could be usedas part of an SQL statements for creation of the corresponding column.This method is overloaded with the string operator. So the two examplesabove are equivalent.

AUTHOR AND COPYRIGHT

  SQL::Schema::Table::Column is Copyright (C) 2000,    Torsten Hentschel    Windmuehlenweg 47    44141 Dortmund    Germany

    Email: toddAATTbayleys.ping.de

  All rights reserved.

  You may distribute this package under the terms of either the GNU  General Public License or the Artistic License, as specified in the  Perl README file.

This document was created byman2html,using the manual pages.