++ed by:
KEEDI ZMUGHAL PERLANCAR SSCAFFIDI

4 PAUSE users
2 non-PAUSE users.

Jens Rehsack
and 1 contributors

NAME

SQL::Statement - SQL parsing and processing engine

SYNOPSIS

  # ... depends on what you want to do, see below

DESCRIPTION

The SQL::Statement module implements a pure Perl SQL parsing and execution engine. While it by no means implements full ANSI standard, it does support many features including column and table aliases, built-in and user-defined functions, implicit and explicit joins, complexly nested search conditions, and other features.

SQL::Statement is a small embeddable Database Management System (DBMS), This means that it provides all of the services of a simple DBMS except that instead of a persistant storage mechanism, it has two things: 1) an in-memory storage mechanism that allows you to prepare, execute, and fetch from SQL statements using temporary tables and 2) a set of software sockets where any author can plug in any storage mechanism.

There are three main uses for SQL::Statement. One or another (hopefully not all) may be irrelevant for your needs: 1) to access and manipulate data in CSV, XML, and other formats 2) to build your own DBD for a new data source 3) to parse and examine the structure of SQL statements.

INSTALLATION

There are no prerequisites for using this as a standalone parser. If you want to access persistant stored data, you either need to write a subclass or use one of the DBI DBD drivers. You can install this module using CPAN.pm, CPANPLUS.pm, PPM, apt-get, or other packaging tools. Or you can download the tar.gz file form CPAN and use the standard perl mantra

 perl Makefile.PL
 make
 make test
 make install

It works fine on all platforms it's been tested on. On Windows, you can use ppm or with the mantra use nmake, dmake, or make depending on which is available.

USAGE

How can I use SQL::Statement to access and modify data?

SQL::Statement provides the SQL engine for a number of existing DBI drivers including DBD::CSV, DBD::DBM, DBD::AnyData, DBD::Excel, DBD::Amazon, and others.

These modules provide access to Comma Separated Values, Fixed Length, XML, HTML and many other kinds of text files, to Excel Spreadsheets, to BerkeleyDB and other DBM formats, and to non-traditional data sources like on-the-fly Amazon searches.

If your interest is in actually accessing and manipulating persistent data, you don't really want to use SQL::Statement directly. Instead, use DBI along with one of the DBDs mentioned above. You'll be using SQL::Statement, but under the hood of the DBD. See http://dbi.perl.org for help with DBI and see SQL::Statement::Syntax for a description of the SQL syntax that SQL::Statement provides for these modules and see the documentation for whichever DBD you are using for additional details.

How can I use it to parse and examine the structure of SQL statements?

SQL::Statement can be used stand-alone (without a subclass, without DBI) to parse and examine the structure of SQL statements. See SQL::Statement::Structure for details.

How can I use it to embed a SQL engine in a DBD or other module?

SQL::Statement is designed to be easily embedded in other modules and is especially suited for developing new DBI drivers (DBDs). See SQL::Statement::Embed.

What SQL Syntax is supported?

SQL::Statement supports a small but powerful subset of SQL commands. See SQL::Statement::Syntax.

How can I extend the supported SQL syntax?

You can modify and extend the SQL syntax either by issuing SQL commands or by subclassing SQL::Statement. See SQL::Statement::Syntax.

How can I participate in ongoing development?

SQL::Statement is a large module with many potential future directions. You are invited to help plan, code, test, document, or kibbitz about these directions. A sourceforge site will be available soon. If you want to join the development team, or just hear more about the development, write Jeff a note (<jzuckerATcpan.org>.

Where can I go for more help?

For questions about installation or usage, please ask on the dbi-users@perl.org mailing list or post a question on PerlMonks (http://www.perlmonks.org/, where Jeff is known as jZed). If you have a bug report, a patch, a suggestion, write Jeff at the email shown below.

ACKNOWLEDGEMENTS

Jochen Wiedmann created the original module as an XS (C) extension in 1998. Jeff Zucker took over the maintenance in 2001 and rewrote all of the C portions in perl and began extending the SQL support. More recently Ilya Sterin provided help with SQL::Parser, Tim Bunce provided both general and specific support, Dan Wright and Dean Arnold have contributed extensively to the code, and dozens of people from around the world have submitted patches, bug reports, and suggestions. Thanks to all!

If you're interested in helping develop SQL::Statement or want to use it with your own modules, feel free to contact Jeff.

BUGS AND LIMITATIONS

  • currently we treat NULL and '' as the same - eventually fix

  • No nested C-style comments allowed as SQL99 says

AUTHOR AND COPYRIGHT

Copyright (c) 2001,2005 by Jeff Zucker: jzuckerATcpan.org

Portions Copyright (C) 1998 by Jochen Wiedmann: jwiedATcpan.org

All rights reserved.

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