Its very simple to install this great application on Ubuntu, i m using the 6.06 Dapper Drake version of Ubuntu, but it should work on any other version, so lets see how to install it:
First of all you need to download the DBDesigner package, you can get it from here:
Grab the rpm version.
After downloading this file you will need alien to convert it to .deb, if you don't have it installed, just type this on a terminal:
sudo apt-get install alien
Now, go to where you downloaded the rpm package and install it using:
sudo alien -i DBDesigner4-0.5.4-0.i586.rpm
And now the trick to get it working, if you try to open the DBDesigner it will give you an error saying that it cant open the shared library libborqt-6.9-qt2.3.so, to fix it do the following:
First Download the library package and extract it using:
tar xzvf kylixlibs3-borqt-3.0-2.tar.gz
After extracting it do the following:
sudo cp kylixlibs3-borqt/libborqt-6.9.0-qt2.3.so /lib/libborqt-6.9-qt2.3.so
Now your DBDesigner should be working, the executable file DBDesigner4 can be found at /opt/DBDesigner
Hope it helps!