DbFramework::Table - Table class

NAME

DbFramework::Table - Table class

SYNOPSIS

  use DbFramework::Table;
  $t    = new DbFramework::Table new($name,\@attributes,$pk,$dbh,$dm);
  $t->init_db_metadata($catalog);
  $dbh  = $t->dbh($dbh);
  $pk   = $t->is_identified_by($pk);
  @fks  = @{$t->has_foreign_keys_l};
  %fks  = %{$t->has_foreign_keys_h};
  @keys = @{$t->is_accessed_using_l};
  @a    = $t->get_attributes(@names);
  @n    = $t->attribute_names;
  $html = $t->as_html_form;
  $s    = $t->as_string;
  $sql  = $t->as_sql;
  $rows = $t->delete($conditions);
  $pk   = $t->insert(\%values);
  $rows = $t->update(\%values,$conditions);
  @lol  = $t->select(\@columns,$conditions,$order);
  @loh  = $t->select_loh(\@columns,$conditions,$order);
  @a    = $t->non_key_attributes;
  $dm   = $t->belongs_to;
  @fks  = $t->in_foreign_key($attribute);
  do_something if $t->in_key($attribute);
  do_something if $t->in_primary_key($attribute);
  do_something if $t->in_any_key($attribute);

DESCRIPTION

A DbFramework::Table object represents a database table (entity).

SUPERCLASSES

DbFramework::DefinitionObject

DbFramework::DataModelObject

CLASS METHODS

new($name,\@attributes,$pk,$dbh,$dm)

Create a new DbFramework::Table object. $dbh is a DBI database handle which refers to a database containing a table named $name. @attribues is a list of DbFramework::Attribute objects. $primary is a DbFramework::PrimaryKey object. @attributes and $primary can be omitted if you plan to use the init_db_metadata() object method (see below). $dm is a DbFramework::DataModel object to which this table belongs.

OBJECT METHODS

Foreign keys in a table can be accessed using the HAS_FOREIGN_KEYS_L and HAS_FOREIGN_KEYS_H attributes. Note that foreign key objects will not be created automatically by calling init_db_metadata() on a table object. If you want to automatically create foreign key objects for your tables you should use call init_db_metadata() on a DbFramework::DataModel object (see init_db_metadata() in the DbFramework::Datamodel manpage). Other keys (indexes) defined for a table can be accessed using the IS_ACCESSED_USING_L attribute. See AUTOLOAD() in the DbFramework::Util manpage for the accessor methods for these attributes.

is_identified_by($primary)

$primary is a DbFramework::PrimaryKey object. If supplied sets the table's primary key to $primary. Returns a DbFramework::PrimaryKey object with is the table's primary key.

dbh($dbh)

$dbh is a DBI database handle. If supplied sets the database handle associated with the table. Returns the database handle associated with the table.

belongs_to($dm)

$dm is a DbFramework::DataModel object. If supplied sets the data model to which the table belongs. Returns the data model to which the table belongs.

get_attributes(@names)

Returns a list of DbFramework::Attribute objects. @names is a list of attribute names to return. If @names is undefined all attributes associated with the table are returned.

attribute_names()

Returns a list of attribute names for the table.

as_html_form()

Returns HTML form fields for all attributes in the table.

in_foreign_key($attribute)

$attribute is a DbFramework::Attribute object. Returns a list of DbFramework::ForeignKey objects which contain $attribute.

in_primary_key($attribute)

$attribute is a DbFramework::Attribute object. Returns true if $attribute is a part of the primary key in the table.

in_key($attribute)

$attribute is a DbFramework::Attribute object. Returns true if $attribute is a part of a key (index) in the table.

in_any_key($attribute)

$attribute is a DbFramework::Attribute object. Returns true if $attribute is a part of a key (index), a primary key or a foreign key in the table.

non_key_attributes()

Returns a list of DbFramework::Attribute objects which are not members of any key, primary key or foreign key.

as_string()

Returns table details as a string.

init_db_metadata($catalog)

Returns an initialised DbFramework::Table object for the table matching this object's name() in the database referenced by dbh(). $catalog is a DbFramework::Catalog object.

as_sql()

Returns a string which can be used to create a table in an SQL 'CREATE TABLE' statement.

delete($conditions)

DELETE rows FROM the table associated with this object WHERE the conditions in $conditions are met. Returns the number of rows deleted if supplied by the DBI driver.

insert(\%values)

INSERT INTO the table columns corresponding to the keys of %values the VALUES corresponding to the values of %values. Returns the primary key of the inserted row if it is a Mysql 'AUTO_INCREMENT' column or -1.

update(\%values,$conditions)

UPDATE the table SETting the columns matching the keys in %values to the values in %values WHERE $conditions are met. Returns the number of rows updated if supplied by the DBI driver.

select(\@columns,$conditions,$order)

Returns a list of lists of values by SELECTing values FROM @columns WHERE rows meet $conditions ORDERed BY the list of columns in $order. Strings in @columns can refer to functions supported by the database in a SELECT clause e.g.

@columns = q/sin(foo),cos(bar),tan(baz)/;

select_loh(\@columns,$conditions,$order)

Returns a list of hashrefs containing (column_name,value) pairs by SELECTing values FROM @columns WHERE rows meet $conditions ORDERed BY the list of columns in $order. Strings in @columns can refer to functions supported by the database in a SELECT clause e.g.

@columns = q/sin(foo),cos(bar),tan(baz)/;

The keys in the hashrefs will match the name of the function applied to the column i.e.

@loh = $foo->select(\@columns);

print "sin(foo) = $loh[0]->{sin(foo)}\n";

as_html_heading()

Returns a string for use as a table heading row in an HTML table.

SEE ALSO

the DbFramework::DefinitionObject manpage, the DbFramework::Attribute manpage, the DbFramework::DataModelObject manpage and the DbFramework::DataModel manpage.

AUTHOR

Paul Sharpe <paul@miraclefish.com>

COPYRIGHT

Copyright (c) 1997,1998,1999 Paul Sharpe. England. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

 DbFramework::Table - Table class