When we create the applications in mobile
- less processing power
- less memory
- small screen
so the concept of highly defined database like SQL,Oracle is not feasible on mobile's
Even some of the company provide good database for j2me like "Perst Lite J2ME Embedded Database","J2ME Polish DB"etc.
But after using 3rd party database or API, the problem for portability arise.
So try to avoid 3'rd party tools , if possible
But in order to run J2ME applications on all mobile's .You have to stick with the RMS(Record Management Store)
The RMS consist of very low level of functionality.
i.e It does not have method's like addRow,addColumn,addTable.etc
So you have to develop your own logic for addRow,removeRow or addColumn etc.
Best of Luck