What would happen if update a javacard applet

[lostsiwonlw]

If amount of data are already stored in javacard, now I want to make some changes in applet and update the applet on javacard.
What would happen to previously stored data on card ?

[UNKNwYSHSA]

I have not met the needs of applet upgrade, We can only remove the old version, install the new version, then the applet data is lost.
We can create a file system cap, all data can be stored in this file system, applet is responsible for processing logic. applet can be upgrade only. But if you want to upgrade the cap of the file system, the data will still lost.