You may use this command for listing the files for your own debuggable apk:

adb shell run-as <sample.package.id> ls /data/data/sample.package.id/cache

And this script for pulling from cache, this copy the content to sdcard first, pull and then remove it at the end:

#!/bin/sh
adb shell "run-as <sample.package.id> cat '/data/data/<sample.package.id>/$1' > '/sdcard/$1'"
adb pull "/sdcard/$1"
adb shell "rm '/sdcard/$1'"

Then you can pull a file from cache like this:

./pull.sh cache/someCachedData.txt

Get Database file via ADB

sudo adb -d shell "run-as com.example.name cat /data/da/com.example.name /databases/STUDENT_DATABASE  > /sdcard/file