I recently installed Pentaho DI 4.4.1. I was previously using PDI 3.2. Transferring my ETL’s to the new PDI installation resulted in this error message (truncated).
Error connecting to database [mysql] : org.pentaho.di.core.exception.KettleDatabaseException: Error occured while trying to connect to the database Exception while loading class org.gjt.mm.mysql.Driver
Digging around, the full error can be found here:
Exception while loading class mysql.Driver
The answer is provided in the Jira ticket. You need to download and install the MySQL JDBC connector which can be found here:
I am using the Windows x64 version so I had to place the jar file here: C:\Program Files\pentaho\design-tools\data-integration\libext
Now I am able to connect to MySQL.
According to Pentaho, they can no longer include the MySQL JDBC connector as it is not compatible with the Apache 4.3 license.