Hi, and thank you fpr your help!
My Java-EE-Server is glassfish.
I dont have much knowledge about tomcat.
I think, I installed the mysq-driver in tje right way.
I have done the following steps below:
Window --> Preferences --> Data Management --> Connectivity --> Driver Definition --> [ADD] --> Vendor Filer [MySQL] --> select [MySQL
JDBC Driver 5.1] --> tab[JAR List] --> [ADD JAR] --> Path to mysql-connector.jar
Even the Data-Source-Explorer finds my database with the correct tables... : (