Platform: IBM Informix Dynamic Server 10.00 Connecting to IBM Informix Dynamic Server – the Open Source Way Jonathan Leffler STSM, IBM Informix Database Engineering Session: K12 2005-05-26 08:30 Agenda • Open Source • Underlying connectivity • ESQL/C • ODBC • JDBC • Perl, DBI, and DBD::Informix • Tcl/Tk, isqltcl • PHP • Python • Ruby 2 Open Source • What is Open Source? • Which rock have you been hiding under? • Software released under an Open Source license • Conformant with the Open Source Definition • Found at http://www.opensource.org/ • Free Redistribution • Source Code • Derived Works Permitted • No Discrimination Against People or Groups • No Discrimination Against Fields of Endeavour • Distribution of License 3 Open Source Licenses • There are many alternative Open Source licenses • GPL – GNU Public License • LGPL – Lesser GNU Public License • BSD – Berkeley Systems Distribution • MIT – Massachussetts Institute of Technology (X) • MPL – Mozilla Public License • Academic Free License • Open Software License • Nearly 60 licenses listed at the Open Source Initiative! 4 Informix Database Connectivity • ESQL/C • The original connectivity. • Standardized in SQL standards (ISO/IEC 9075:1992 onwards). • ODBC • Originally defined by Microsoft. • Standardized (as CLI) by ISO/IEC 9075-3:1996. • JDBC • Java analogue of ODBC. • Standardized by Sun. • All of these are proprietary. • But can be used with Open Source software. 5 ESQL/C • Preprocessor which converts extended C into pure C. • Links with specific libraries. • Permits separation of static and dynamic SQL. • Even though Informix does not really do so. int main(void) { EXEC SQL WHENEVER ERROR STOP; EXEC SQL DATABASE Stores; EXEC SQL BEGIN WORK; EXEC SQL DROP TABLE Customer; EXEC SQL ROLLBACK WORK; return(0); } 6 ODBC • Database agnostic. • Separates driver manager from drivers. • Different drivers can be loaded at run time. • With care, you can avoid database-specific features. • But sometimes you want to use them. • All statements are dynamic. • De-emphasized by Microsoft • In favour of newer technologies • ADO • .NET 7 JDBC • Database agnostic. • Drivers have different levels of Java-ness. • Type 4: pure Java – usually the best type to use. • The only other way to connect is ESQL/J. • Not widely accepted. • JDBC is the lingua franca of the Java database world. 8 Perl, DBI, and DBD::Informix • Perl • DBI • DBD::Informix • Apache • mod_perl 9 Perl – Practical Extraction and Report Language • Originally written by Larry Wall • Version 1.0 in 1987 • Version 4.0 in 1991 under GPL and Artistic License • Version 5.0 in 1994 • Current stable versions: • 5.8.6 — November 2004 • 5.6.1 — August 2001 • 5.005_03 — April 2000 • Obtain via CPAN • Comprehensive Perl Archive Network • http://www.cpan.org/ 10 Perl • Script Language • Does not require compilation • Complex looking code • Can be incredibly terse • Can be quite legible • Excellent at string handling • Excellent access to operating system 11 Remove RCS Keyword Markers • #!/usr/bin/perl -wp • s/\$([A-Z][a-z]+|RCSfile): ([^\$]+) \$/$2/go; • TMTOWTDI • There’s more than one way to do it! • (Yes, you could use sed for this) • perl -wp -e ’s/\$\w+: ([^\$]+) \$/$1/go;’ $* 12 File Renaming #!/usr/bin/perl # @(#)$Id: rename.pl,v 1.1 1992/01/05 22:33:47 jl Exp $ # Rename files using a Perl substitute command ($op = shift) || die "Usage: $0 perlexpr [filenames]\n"; if (!@ARGV) { @ARGV = <STDIN>; chop(@ARGV); } for (@ARGV){ $was = $_; eval $op; die $@ if $@; rename($was, $_) unless $was eq $_; } 13 Perl Database Interface • DBI written by Tim Bunce. • Standard way to access databases with Perl. • Many database drivers available. • Including ODBC, DB2, and Oracle. • And, of course, Informix. • And many others. • Current version 1.48 – March 2005. • Requires Perl 5.6.1 or later. • Using Perl and a database? Use DBI! • Or a module built on top of DBI. 14 The Cheetah Book • The ‘bible’ for Perl DBI • Authors: • Alligator Descartes • Tim Bunce • O’Reilly, February 2000 • ISBN 1-56592-699-4 • http://www.oreilly.com/ 15 DBI - Database Handles • Load DBI • use DBI; • Create database handles • $dbh = DBI->connect(‘DBI:Informix:stores7’); • Database methods • $dbh->do(‘DELETE FROM Customer’); • Transaction control • $dbh->rollback; • $dbh->commit; • Disconnect • $dbh->disconnect; 16 DBI - Statement Handles • Create statement handles • $sth = $dbh->prepare(qq{ DELETE FROM Customer WHERE Lname LIKE ‘%$name%’ AND ZipCode IS NULL }); • Statements can be executed • $sth->execute(); • Statement handles can be released • Implicitly • Statement handle goes out of scope • Explicitly • undef $sth; 17 DBI - Handling SELECT • Statement handles are used for SELECT too • $sth = $dbh->prepare(qq% SELECT * FROM Customer WHERE Fname = ? AND Lname = ? ORDER BY Lname, Fname%); • $sth->execute($firstname, $surname); • @results = $sth->fetchall_arrayref; • …process results • print $results[$rownum][$colnum], etc • undef $sth; • SELECT is fairly simple 18 DBI - Handling SELECT • Many ways to fetch rows • $sth->fetchrow_array • $sth->fetchrow_hashref • $sth->fetchrow_arrayref • $sth->fetchall_arrayref • All rows • Also utility methods • $dbh->selectrow_array • First row only • $dbh->selectall_arrayref 19 DBD::Informix - at last • Using DBD::Informix is using DBI • All the examples work with DBD::Informix • Current version is 2005.01 – March 2005 • Building DBD::Informix is easy • Requires working ESQL/C 5.00 or later (eg ClientSDK) • ANSI C compiler (code uses prototypes) • Test database with DBA privileges • Perl version 5.6.0 or later • 5.8.6 (or, at a pinch, 5.6.1) strongly recommended • DBI version 1.38 or later • Version 1.48 or later strongly recommended 20 Installing DBD::Informix • Download software from CPAN • cd DBD-Informix-2005.01 • more README • perl Makefile.PL • make • make test • make install • Have fun! • Same rules apply to all Perl modules • Building Perl modules is easy! 21 DBD::Informix - example #! /usr/bin/perl -w use DBI; $dbh = DBI->connect(‘DBI:Informix:stores7’,’’,’’, {RaiseError => 1, PrintError=>1}); $sth = $dbh->prepare(q%SELECT Fname, Lname, Phone FROM Customer WHERE Customer_num = ? %); $sth->execute(106); $ref = $sth->fetchall_arrayref(); for $row (@$ref) { print “Name: $$row[0] $$row[1], Phone: $$row[2]\n”; } $dbh->disconnect; 22 DBD::Informix & AutoCommit • AutoCommit is on by default • To comply with DBI requirements • Cannot be unset on unlogged databases • Simulates MODE ANSI on logged databases • Explicit BEGIN WORK is possible • $dbh->do(‘begin work’); • $dbh->{AutoCommit} = 0; • $dbh = DBI->connect(‘DBI:Informix:stores7’, ‘’, ‘’, { AutoCommit => 0 }); 23 Standard DBI Information • Standard database attributes • $dbh->{Driver} • $dbh->{AutoCommit} • $dbh->{PrintError} • $dbh->{RaiseError} • $dbh->{ChopBlanks} • There are others, too. 24 Standard DBI Information • Standard statement attributes • $sth->{Statement} • $sth->{CursorName} • $sth->{NUM_OF_FIELDS} • $sth->{NUM_OF_PARAMS} • $sth->{NAME} • $sth->{TYPE} • $sth->{NULLABLE} 25 Standard DBI Information • Standard handle attributes • $h->err • $h->errstr • $h->state • Standard handle methods • $h->trace($trace_level) • $h->trace_msg(“message”) 26 Informix-only Information • SQLCA is available • $sth->{ix_sqlcode} • $sth->{ix_sqlerrd} - an array • $sth->{ix_sqlerrm} • $sth->{ix_sqlerrp} • $sth->{ix_sqlwarn} - an array 27 Informix-only Information • Non-standard attributes • $dbh->{ix_InformixOnline} • $dbh->{ix_LoggedDatabase} • $dbh->{ix_ModeAnsiDatabase} • $dbh->{ix_InTransaction} • $dbh->{ix_ConnectionName} • Standard attribute • $dbh->{Name} — database name 28 Informix-only Information • Non-standard attributes • $drh->{ix_ProductVersion} • a version number for ESQL/C • $drh->{ix_ProductName} • $drh->{ix_MultipleConnections} • $drh->{ix_ActiveConnections} • $drh->{ix_CurrentConnection} • $drh->{ix_ServerVersion} • a version number for the database server • All these attributes can also be found via the database handle, $dbh 29 Informix-only Information • Non-standard attributes • $sth->{ix_NativeTypeName} • $sth->{ix_ColType} • $sth->{ix_ColLength} 30 DBD::Informix • Known Limitations: • Not yet fully aware of 9.x collection types or UDTs. • No support for bind_param_inout method. • No handling for most new DBI features since v1.14. • Version 1.00.PC2 was an official Informix product. • Officially “IBM Informix Database Driver for Perl”. • Version 2003.04 was officially not an IBM product. • The support channel is the mailing list: • [email protected] • [email protected] • [email protected] 31 DBD::Informix Documents • Primary References • Pre-install • README file • Files in Notes sub-directory • Post-install • perldoc DBI • perldoc DBD::Informix • Books • Programming Perl, 3rd Edition • Programming the Perl DBI 32 DBD::Informix - Web Sites • Use CPAN to obtain the software • http://www.cpan.org/ • http://search.cpan.org/ • perl –MCPAN –e ‘install Bundle::DBD::Informix’ • DBI web site • http://dbi.perl.org/ • Sign up for [email protected] mailing list • Help yourself - join the mailing list! 33 Apache • Apache Web Server • Most widely used web server • Version 1.3.33 • unless there’s a new version this week • Or Version 2.0.52 • Modular structure • Allows special purpose modules to be added • mod_jserv - Java Server • mod_perl - Perl Interpreter 34 Apache, Perl and CGI • CGI scripts drive the web • Many of them are Perl scripts • Most of those use the CGI module • http://www.somewhere.com/cgi-bin/script.pl • Giveaway that there’s a Perl script in use • Often