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Working with the Apache Derby Database and ColdFusion
A basic introduction
Oct. 13, 2007 08:15 PM
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Working with the Network Server Using ij
If you're
really interested in using Derby, you'll probably want to install its
tools. Adobe includes the tools classes in the base install, but
doesn't include the nice scripts that are part of the Derby
distribution and make using the tools that much easier. If you've
downloaded Derby, you can copy the contents of its bin directory into
ColdFusion's. This gives you scripts like sysinfo and dblook that you
can use to get information about your Derby installation and its
databases. Also included is ij, a SQL*Net-like console for
interactively sending SQL commands to either an embedded or network
database.
Navigate to the bin directory where you installed the Derby scripts.
Open a command prompt and run setNetworkClientCP. Now run ij. The
program will echo its version and give you a new command prompt:
ij Version 10.2
ij>
Now connect to the database you created with the
ColdFusion Administrator (named test2 in the screenshot above) by
typing this at the command prompt: CONNECT
'jdbc:derby://localhost:1527/test2;create=true'; Ij will return a
prompt and you're connected. You can now start creating tables and
having lots of fun. To be honest, unless you're used to interacting
with your database on the command line, you'd be better off sending
your CREATE TABLEs through CFQuery or better yet, using IBM's Eclipse
plug-in.
Using IBM Cloudscape Workbench Plug-in for Eclipse
IBM provides an excellent plug-in for working with databases. You can
use it to connect to DB2, Oracle, SQL Server, MySQL, Sybase, Informix,
and oh, yeah, Derby. You can then use a nifty tree-type browser to
navigate the objects in your database. There's no visual query builder
or simple table creation dialog, but if you want to explore a database,
sample table data, or test your queries inside of Eclipse it's not bad.
Get started by visiting IBM DeveloperWorks and downloading the CS
Workbench plug-ins (skip the StandAlone version): www.ibm.com/developerworks/db2/downloads/csworkbench/.
Unpack the csworkbench_plugins_1.0.zip archive into your Eclipse
installation and restart Eclipse if necessary. Go to the Window
menu->Show View->Other... and select Data->Database Explorer.
Now you have a new View open at the bottom of your screen with a folder
labeled Connections. Right-clicking on this let you create a New
Connection. You can give it a whirl with one of the example embedded
databases. You have to tell Eclipse the Database Location and the
location of the Derby driver (which is in derby.jar). (Figure 4)
Remember that once you connect to an embedded database with Eclipse,
ColdFusion won't be able to until you Disconnect. If you so much as
Verify your Datasource in ColdFusion, you won't be able to connect with
Eclipse until you restart the CF server. If you created a network
database and have the Derby server running, you can connect to that
without worrying about locking the connection. Select Derby Client JDBC
Driver from the list in the New Connection dialog instead. The
screenshot below shows the Derby Client dialog. It looks like a
resource bundle got misplaced in my install, so NO_RESOURCE_FOUND is
showing where 'JDBC Driver Class,' 'Class Location,' and 'Connection
URL' should appear. In this case 'Class Location' should indicate the
location of derbyclient.jar. Even if you didn't specify a password when
you created your database, you'll have to specify one here.
Here you can see the database browser contents for the Book Club
example database. Right-clicking on a table gives you the option to
browse the table data.
Packaging Your Database for Distribution
One of
the prime reasons for using Derby is to make it easy for other
ColdFusion users to install your system. You know the target database
platform exists on all ColdFusion 8 servers, regardless of operating
system. So how do you package your application for deployment on the
machines of your potential clients? Use the Packaging and Deployment
wizard in ColdFusion Administrator. There isn't enough space here to
cover this feature fully, but it's easy enough to figure out. If you
want to package up your CF files, Derby database, and Datasource,
simply add the directory containing your application and the directory
containing your Derby database under "Assoc. Files/Dirs" in the wizard.
Next add the Datasource. Build your Archive and send it out to your
client. They should be able to use the same wizard in reverse. If the
database files are placed in the same location relative to Derby, the
Datasource should continue to work. If the deployer changes the
database deployment path, he will have to update the Datasource to
reflect this change.
Conclusion
Derby is very well documented and you can find stacks of reading material to fill your free time at http://db.apache.org/derby/.
This article is a basic introduction to get you started using Derby as
installed with ColdFusion 8. For more technical details on performance,
SQL standard compatibility, and Derby's Java API, head to Apache. Since
Derby's whole API is exposed in Java, it plays very nicely with CF. You
can do all sorts of crazy things directly to the database - imagine
creating a whole new database (in two lines of CFScript), then
populating it, zipping it up, and sending it to the browser embedded in
an applet. It's not hard to think of a system that creates and packages
offline systems... sounds like a good article.
References
http://db.apache.org/derby/
http://wiki.apache.org/db-derby/SQLvsDerbyFeatures
www.ibm.com/developerworks/db2/downloads/csworkbench/
http://squirrel-sql.sourceforge.net/index.php?page=faq
At press time, ColdFusion 8 was still in beta and the documentation incomplete.
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About Chip TemmOver the past decade, Chip Temm moved from North America to Europe and on to Africa where his company anthroLogik solutions provided analysis and development services to non-governmental organizations across seven timezones. He is currently back in Washington, DC where "remote development" means working from home and "wildlife" means raccoon.