Fail to list files on adb shell

i'm trying to access my database file from adb shell, but sqlite3 cant open it, i think this is because i dont have root, searching on the web i found that to get root acess you need to:

adb root ->adbd is restarted as root(dont really know what is this)
adb connect <device>
adb -s <device> shell

this commands work fine here, but i still cant get root access and still cant acess my database file

The error i'm getting is:

Error: unable to open database "ClientsInfoDB.db": unable to open database      file 1

on my app code to create the database i use:

    public DatabaseHelper(Context context){
    super(context, "ClientsInfoDB", null, 2);

can anyone help me here? thanks for attention