NAME
SQL::DB::Schema - Table and column definitions for SQL::DB
VERSION
0.19_10. Development release.
SYNOPSIS
use SQL::DB::Schema qw/load_schema/;
my $schema = SQL::DB::Schema->new(name => 'myschema');
$schema->define(@table_1_definition);
$schema->define(@table_2_definition);
$schema->define(@table_3_definition);
...
$schema->define(@table_N_definition);
# Build INSERT expressions using irows:
my ($table_1, $table_3) = $schema->irow(qw/table_1, table_3/)
# Build INSERT/UPDATE/DELETE expressions using urows:
my ($table_1, $table_3) = $schema->urow(qw/table_1, table_3/)
# Build SELECT expressions using srows:
my ($table_1, $table_2) = $schema->srow(qw/table_1, table_2/)
# Retrieve a previously elsewhere created schema:
my $other = load_schema('other');DESCRIPTION
SQL::DB::Schema objects hold the table and column definitions used by SQL::DB for creating SQL queries.
The SYNOPSIS and this documentation show how this module is used but you should never write such code by hand. Schema information is either automatically retrieved by SQL::DB at run-time or pre-generated with the sqldb-schema(1) command-line program.
A single function is exported on request:
- load_schema($name) -> SQL::DB::Schema
-
$name + '::$driver' (where $driver is a DBD driver name) must be the name of a class which when loaded creates a schema called $name + '::$driver'. See sqldb-schema for how to generate such a class.
CONSTRUCTOR
- new(name => $name) -> SQL::DB::Schema
-
Create a new schema object. The 'name' attribute is required and must be unique. The created schema is stored in an internal hash and can be retrieved from other lexical scopes using the "load_schema" function.
METHODS
- define( \@column_info )
-
Add table/column information to the schema. The \@column_info array-reference must be the same as the structure returned from a DBI "column_info()" call. This method will confess if duplicate column information is given.
- not_known(@tables) -> @not_known
-
Returns the @tables which are not known in the schema.
- irow( $table, [ $table2 ] ) -> CODEref
-
Returns coderefs representing $table(s). Each coderef called with column names returns a string suitable for an INSERT operation. These coderefs can be used in SQL::DB's "do()" method (for INSERT queries).
- urow( $table, [ $table2 ] ) -> SQL::DB::Expr based objects
-
Returns objects representing abstract rows from $table(s). Each object has a method for each column in the table. These urow objects can be used in SQL::DB's "do()" method (UPDATE or DELETE queries).
- srow( $table, [ $table2 ] ) -> SQL::DB::Expr based objects
-
Returns objects representing abstract rows from $table(s). Each object has a method for each column in the table. These srow objects can be used in SQL::DB "fetch()" and "fetch1()" methods (for SELECT queries).
SEE ALSO
AUTHOR
Mark Lawrence <nomad@null.net>
COPYRIGHT AND LICENSE
Copyright 2007-2011 Mark Lawrence <nomad@null.net>
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.