Setting up Grails project on Oracle XE database

-

If you have some code already working on another database, say Postgres, and you want to set it up on Oracle XE database, there are some things to consider.

You have to change the application data source (conf/DataSource.groovy) and move the Oracle jdbc driver to /lib - all that is explained pretty well here.

Basically the result will be something like this:

You might have some troubles with the url, here is a little explanation:

  • I'm running the XE database on my local host, hence the host is: 127.0.0.1.
  • 1521 is the default database listener port for Oracle XE
  • XE is the default SID for Oracle XE

Oracle XE and port setup

While we are talking about ports. The default http interface port for Oracle XE management through APEX is 8080 and it might be in collision with other software you are running, like our grails app.

You can read on here to find out the way to check default ports and those set on your configuration and also how to change them.

Oracle XE and reserved words

If you are seeing a lot of stack traces while running your grails app on the new configuration, chances are that your domain classes use field names that are reserved in a Oracle database. Try to stop the start up before all the stacktraces. If you see something like: "table could not be created" and "ORA-00904 Invalid identifier" run "select * from v$reserved_words" and check if your domain names or field names collide with the reserved words.

Comments

Post a Comment

Popular posts from this blog

Android Virtual Machine and non-ASCII characters the path

-
Image
I have found a job ! =) For a month (and hopefully more) I'll be working at Espeo Software. I've started last Wednesday and I've really enjoyed it so far. Currently I'm working on an android app. During its developement I've encountered a bug when trying to launch the AVM on Windows with a profile containing the letter 'Ł'. This is the message I got : ERROR: no search paths found in this AVD's configuration. Weird, the AVD's config.ini file is malformed. Try re-creating it. It appears that while the sdk can be in a folder with such a path that contains non-ASCII character the emulator does not like it. Specifically to .android/avd which on default is stored in your windows user folder. The solution is to add a local user/system variable ANDROID_SDK_HOME with the path to a place you want .android to be. For example ANDROID_SDK_HOME=C:\AndroidDev. You might have to restart your Eclipse or other IDE after doing that. But that fixed it
Read more

MongoDB and distinct values in arrays

-
This post is a mini-tutorial on how to deal with array fields in MongoDB, specifically arrays of items that may or may not be duplicated. Let's create a collection of unicorns, smilarly to  The Little MongoDB Book examples: Find should now return something like this, the _ids will vary: Adding a value into an array We've found out that our unicorn Scott also loves playing games, so lets push a new value into our document's loves array: Using push , we could insert into our the same value multiple times. Pushing a value if its unique We have found out that all our unicorns love movies and want to update the whole collection. Unfortunately Scott already has got movies in his loves field. As shown here , we can use addToSet , which won't add a duplicated value to an array: The third parameter of update is upsert (false by default). The fourth is multi which makes the query update every document that matches the criteria (false by default meaning th
Read more

Installing FANN on Java project and NativeLibrary.loadLibrary problems with 32bit/64bit

-
If you try to install FANN  and get it working with a Java project you might run into a few problems. The whole process is explained on the fannj (the Java binding) project's wiki but not in great detail. Installing Fannj Get fannj Store it somewhere and add the jar to your project. Get FANN Extract it somewhere. Set up the DLL by either: copying the fannfloat.dll to System32, or adding the following line before you try to use FANN:  System.setProperty("jna.library.path", [fannfloat.dll dir path]); Solutions to common issues No Java Native "Exception in thread "main" java.lang.NoClassDefFoundError: com/sun/jna/Platform" Solution : Download the JNA and add the jar to your project. Can' find the FANN library Exception in thread "main" java.lang.UnsatisfiedLinkError: Unable to load library 'fannfloat': The specified module could not be found. Solution : Add debugging code (or better yet: use a debugger) after y
Read more